US 7167794

I'll search for authoritative information on this patent number, including any litigation activity.

Let me check for any litigation, PTAB, or CAFC activity referencing this specific number.

US Patent 7,167,794 — Summary

Important disambiguation notes up front (per the "interpret identifiers literally" rule):

• The identifier 7167794 resolves in the US to patent US 7,167,794 B2 (application US 11/214,994) — the subject of the supplied full text.
• A different, unrelated document also carries the number JP 7167794 B2 (Japanese Patent No. 7167794, granted 2022-11-09, Mitsubishi Electric Building Solutions, a "clip guide mounting work support device" for passenger conveyors). This is a cross-jurisdiction number collision, not the same family and not relevant here.
• I found no CAFC 2026 docket, district court case, or PTAB proceeding referencing 7,167,794. My searches surfaced unrelated 2026 Federal Circuit activity (e.g., Contour IP Holding v. GoPro, Fed. Cir. No. 2026-2012). I could not directly query the USPTO Patent Public Search or the Federal Circuit's PACER/docket system from this session, so I cannot state with certainty that no litigation exists — only that nothing appeared in my searches.

Bibliographic data

Abstract (as issued)

A control apparatus for an internal combustion engine can detect a tubing disconnection failure of an intake pressure sensor so as to warn a user and enable appropriate countermeasures. A control unit controls the engine based on a throttle opening, an intake pressure measured by an intake pressure sensor, and a rotational speed and a crank angle of the engine. The intake pressure sensor is connected to the intake system through tubing. The control unit includes a failure diagnosis section that detects an abnormality of the intake pressure sensor. The failure diagnosis section detects an open circuit or a short circuit of a signal line between the intake pressure sensor and the control unit based on a change in the intake pressure, and also detects a disconnection failure of the tubing of the intake pressure sensor.

Background / problem addressed

On a motorcycle, packaging constraints require the intake pressure (MAP) sensor to be mounted remotely and joined to the intake manifold by tubing. If the tubing comes off, the sensor reads atmospheric pressure — indistinguishable from a wide-open-throttle condition. The conventional apparatus (cited as JP 2002-295300 A, Toyota) could only detect signal-line open/short faults, so a tubing disconnect would be misread as full-open throttle, causing over-fueling, high HC/CO emissions, exhaust afterburning, and an undiagnosed failure. The invention adds tubing-disconnect diagnosis.

Plain-language overview of the independent claims

Claim 1 — Tubing-disconnect diagnosis gated by idle detection (the core invention)
An engine control apparatus has four sensing parts — throttle opening, intake pressure, crank angle, and rotational speed — feeding a control unit that runs the engine. The intake pressure sensor is coupled to the intake system through tubing. The control unit's failure-diagnosis section (a) detects a signal-line open-circuit or short-circuit between sensor and control unit based on change in intake pressure, and (b) also detects a disconnection failure of the tubing. Separately, an idle-detection section determines when the engine is idling. When, during idle, the amount of change in intake pressure within one control period falls to a predetermined amount characteristic of a fully-open throttle, the diagnosis section concludes the sensor tubing is disconnected. In short: use the "flat/no-pulsation MAP signal" as the disconnect signature, but only while idling so as not to misjudge high-load operation.

Claim 5 — Dual-sensor limp-home (the fault-tolerant control invention)
The apparatus has the same sensing architecture and the same dual-capability failure diagnosis (signal-line open/short plus tubing disconnect). Additionally, the engine is multi-cylinder and the intake pressure detection part includes one intake pressure sensor per cylinder measuring each cylinder's intake pressure individually. When either sensor is judged abnormal, the control unit controls the cylinder whose sensor failed by substituting the intake pressure reading from the sensor judged normal. In short: on a per-cylinder MAP-sensor system, if one sensor (or its tubing/line) fails, keep running the engine using the good sensor's signal.

Dependent claims

• Claim 2: the "amount of change" is computed as the differential pressure between the maximum intake pressure on the exhaust stroke and the minimum intake pressure on the intake stroke (ΔP = Pmax − Pmin).
• Claim 3: the engine is a V-type two-cylinder engine for a motorcycle.
• Claim 4: a warning device (e.g., warning LED) is connected to the control unit, which drives it when a tubing disconnect is detected.
• Claim 6: V-type two-cylinder motorcycle engine (depends from claim 5).
• Claim 7: warning device driven on detected tubing disconnect (depends from claim 5).

Operational detail (from the specification / Fig. 5)

The diagnosis polls sensor data each cycle; over one 720° CA control cycle it tracks Pmax (exhaust stroke, ≈atmospheric) and Pmin (intake stroke). Failure diagnosis is executed only if rotational speed Ne < a threshold Neo and throttle opening θ < a threshold θo (i.e., idle/low-load — steps S107/S108 act as the idle-detection section). It then computes ΔP; if ΔP < ΔPo (a threshold set to the disconnect-condition upper limit at idle), a failure flag is set (S111); otherwise it is cleared (S112). At full-open throttle or off-idle, the determination is inhibited to avoid false positives. On detection of a fault, the second embodiment's per-cylinder sensors allow substitution of a good sensor's signal and continued engine control (injector quantity/timing, ignition timing, stroke identification, atmospheric-pressure estimation).

Prior art cited on the face of the patent

• US 4,483,299 A — Honda Motor Co. (1984-11-20)
• US 6,588,259 B2 — Harley-Davidson Motor Company Group, Inc. (2003-07-08)
• JP 2002-295300 A — Toyota Motor Corp. (2002-10-09) — the "first patent document" described in the Background
• Additional family-cited references include EP 0581151 A1, JP 3136968 B2, JP 3741290 B2, and KR 100428295 B1.

Confidence / uncertainty statement

• Bibliographic data, claims, abstract, and description are taken from the authoritative full patent text supplied (Google Patents, US 7,167,794 B2), which I treat as controlling; the same content also appears at patents.justia.com/patent/7167794.
• The current assignee field (Mitsubishi Electric Mobility Corporation) reflects the 2024 "company split" recorded in the patent's legal events; assignment listings are the database's representation and were not independently confirmed against USPTO assignment records in this session.
• No litigation/CAFC/PTAB record for 7,167,794 was found, but I could not run direct queries against PACER, the Federal Circuit docket, or USPTO Patent Public Search, so absence of litigation is reported as "not found in searched sources," not as a verified negative.
• I did not independently verify the German or Japanese family members beyond the identifiers listed.

I'll search for litigation involving US patent 7167794.

Let me search additional litigation-specific sources.

Let me try docket-specific searches.

Litigation Search: US Patent No. 7,167,794

Bottom line: I could not identify any litigation involving US Patent No. 7,167,794.

What I searched

I ran targeted searches across litigation-oriented sources (Unified Patents litigation portal, CourtListener/RECAP, PACER-derived dockets, Docket Alarm, and general web/CAFC coverage) using the exact identifiers 7167794, 7,167,794, and combinations with the patent owner ("Mitsubishi Electric") and subject matter ("internal combustion engine," "intake pressure sensor," "motorcycle").

Results

No case — federal district court, ITC Section 337, or CAFC appeal — asserting, challenging, or otherwise involving US 7,167,794 turned up. Specifically:

• No Unified Patents / PTAB challenge: The Google Patents page for US 7,167,794 lists no AIA trial (IPR/PGR/CBM) history and no "Litigation" section. Its US citation trail is limited to prosecution reference material, not litigation activity.
• The 7167794-type hits are false positives and do not refer to this patent. Per the strict rule to interpret identifiers literally, note these are distinct documents, not US 7,167,794:
  • JP 7167794 B2 — a Japanese patent (特許第7167794号, registered 2022-10-31) titled "クリップガイド取付作業支援装置" (clip guide mounting work support device) belonging to Mitsubishi Electric Building Solutions. Same number, different jurisdiction and different invention.
  • AU 7167794 A — an Australian application number (AU71677/94) for "Apparatus for cutting logs of wood or the like" (AU 684527 B2).
  • A Brazilian municipal court attendance record (ATA 28/04/2020, RS) listing "7167794" as a person's enrollment/ID number.
• Assignee/prosecution context (from the patent record) shows only ordinary ownership changes — Mitsubishi Denki K.K. → Mitsubishi Electric Corporation → Mitsubishi Electric Mobility Corporation (company split, 2024) — with no litigation noted.

Caveats on confidence

• US 7,167,794 issued in 2007 to Mitsubishi Electric for an automotive/motorcycle ECU diagnostic feature. Such component-level patents are typically asserted (if at all) against aftermarket/competitor ECU suppliers, and might appear in a state-court or foreign proceeding that public patent-litigation aggregators do not fully index. My search would not reliably capture those.
• I did not have direct, live access to a complete PACER full-text docket search in this session; my conclusion rests on the litigation aggregators and general web sources listed above. If you need a belt-and-suspenders check, a direct PACER "Nature of Suit: 830 – Patent" party search for "Mitsubishi Electric" combined with the patent number in Docket Alarm, Lex Machina, or RPX Insight (paid databases) would close that gap.

Requested table (nothing to populate)

If you can tell me whether you're specifically looking for US federal suits, ITC investigations, or foreign proceedings, I can refine the search accordingly.

I'll verify the structured-data finding against live sources before concluding.

Let me run more targeted searches on the patent number with litigation/PTAB terms.

Two more confirmation searches — one on litigation, one on the patent's Google Patents litigation tab.

PTAB Proceedings — U.S. Patent No. 7,167,794 B2

"Control apparatus for an internal combustion engine" · Mitsubishi Electric Corp. (now Mitsubishi Electric Mobility Corp.) · Inventor: Yousuke Fukuzawa
Priority 2005-04-12 (JP 2005-114483) · Filed 2005-08-31 · Granted 2007-01-23 · Expired 2025-08-31

Proceedings overview

There are zero AIA trial proceedings on file against US 7,167,794 B2. The canonical structured source ("PTAB proceedings on file," sourced from the USPTO Open Data Portal) returns no IPR, PGR, or CBM proceeding, and my live searches surfaced none either — no petition, no institution decision, no Final Written Decision, and no Federal Circuit appeal arising from a PTAB case. The breakdown is therefore: 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials. The patent has never been tested at the Board.

The bottom line for a defendant is unusual and mostly favorable, but not because the patent was hardened by surviving IPRs — it survived by never being attacked. Two facts dominate the defensive posture: (1) all seven claims (1–7) are UNTESTED at the PTAB and stand unamended; and (2) the patent term expired on 2025-08-31, roughly 13 months before today, having run its full 20-year term (the 12th-year maintenance fee was paid 2018-07-12, so this was expiration by term, not lapse for non-payment). An expired patent cannot support prospective injunctive relief; the exposure is limited to past damages within the 35 U.S.C. § 286 six-year lookback. There is no PTAB "kill shot" to cite, and equally no PTAB estoppel to worry about.

Per-proceeding detail

None. There are no proceedings to report, so the per-proceeding template is intentionally empty. I am not filling it with placeholder or reconstructed proceeding numbers — inventing an IPR number here would be the single most damaging error in a PTAB diligence memo.

Below is what I did verify, so you can see the search was real and the null result is meaningful:

Caveat, stated plainly: a null search result is evidence of absence, not proof of it. Pre-AIA patents with no litigation history are frequently never indexed into the secondary databases that surface in general web search. The ODP structured feed is the authoritative record, and it is consistent with my searches. If you are preparing a formal invalidity opinion or an IPR-estoppel analysis, re-run the query directly against PTAB E2E (https://ptacts.uspto.gov/) and USPTO PatentCenter for Application No. 11/214,994 before relying on this memo as conclusive. If you want that re-run done against the live E2E interface rather than the ODP feed, say so and I'll pull it.

Statutory availability, for completeness: this is a pre-AIA patent (effective filing date 2005-08-31). PGR was never available (PGR requires an effective filing date on or after 2013-03-16). CBM was never available (the claims are directed to internal-combustion-engine sensor diagnostics — a technical invention, not a "financial product or service"; the CBM program also sunset for new petitions on 2020-09-16). IPR was the only vehicle, and nobody used it. Note that IPR remains technically available even against an expired patent (the Board applies Phillips construction and patent owners cannot amend), but the economic incentive is essentially gone for a patent that expired 2025-08-31.

Strategic summary

Claim status: everything is UNTESTED. No claim of the '794 patent has been canceled, disclaimed, or narrowed by any AIA trial. All seven claims — independent claims 1 and 5, and dependents 2, 3, 4, 6, 7 — remain in force as granted, subject only to the ordinary presumption of validity and the fact that the term has now run. Because the patent expired 2025-08-31, there is no live coverage: you cannot infringe an expired claim prospectively, and any theory must be built on past acts within the six-year § 286 window (i.e., conduct on or after roughly 2019-09-28, and before 2025-08-31).

Estoppel landscape: clean, no bars. Section 315(e)(2) estoppel only attaches to a petitioner that obtained an institution decision. There is no petitioner here, so no party is estopped from raising any ground — § 102, § 103, and § 112 defenses are all unimpaired, including grounds that "reasonably could have been raised" at the Board. That cuts both ways: your opponent likewise faces no estoppel or IPR record to distinguish. Practically, your invalidity case will be litigated from scratch on the art cited on the face of the patent (US 4,483,299 to Honda; US 6,588,259 to Harley-Davidson; JP 2002-295300 to Toyota) plus anything you develop — and the '794 claims are unpreserved by any prior Board construction, so claim-construction risk falls on the patent owner, not on you.

Pattern signals: none of the usual markers. No serial petitioner, no defensive aggregator (no Unified Patents, RPX, or similar entity appears anywhere in the chain), and no patent-owner appellate aggressiveness — there is no appeal history because there is no PTAB history. The family shows the usual multinational footprint (JP 4335167 B2 and DE 10 2005 047724 B4 counterparts; the German member is marked Expired – Fee Related), and the patent has a small forward-citation tail including US 2015/0152802 A1 / US 9,810,171 B2 (Ford Global Technologies, manifold pressure sensor offset) — useful only as evidence that the art space stayed active, not as a validity attack. The combination of never asserted in any court I could find + never challenged at the PTAB + expired at full term without ever being licensed into a visible enforcement campaign suggests this patent is a portfolio artifact rather than an asserted asset. That matters: if a demand letter cites US 7,167,794, the letter is likely a low-quality or boilerplate assertion, and the expiration date is a complete defense to any forward-looking royalty demand.

Recommended next steps

1. Do not build a defense around an IPR. There is nothing to invalidate prospectively and an IPR on an expired patent is a waste of budget. The correct first move is a standing/expiration check: confirm the asserted conduct predates 2025-08-31 and falls within the § 286 six-year lookback. If the demand letter threatens ongoing royalties or an injunction, respond that the patent expired 2025-08-31 (full-term expiration; 12th-year fee paid 2018-07-12 per USPTO fee records) and no prospective relief is available.

2. Verify the null result directly, then document it. Pull Application No. 11/214,994 in USPTO PatentCenter and search PTAB E2E (https://ptacts.uspto.gov/) for proceedings involving Patent No. 7,167,794. Archive the results. A contemporaneous, date-stamped confirmation of "no PTAB activity" is the kind of evidence that undercuts any suggestion of a hidden prior challenge.

3. Shift the invalidity effort to district court and to the file history. With no § 315(e)(2) estoppel anywhere in the chain, the full universe of prior art is available in litigation. Start with the three references of record — US 4,483,299 (Honda, 1984-11-20), JP 2002-295300 (Toyota, 2002-10-09), and US 6,588,259 (Harley-Davidson, 2003-07-08) — and note that the specification itself concedes in the "Description of the Related Art" that detecting signal-line open/short faults from intake-pressure change was already known, with the sole asserted novelty being tubing-disconnection detection via differential pressure (ΔP = Pmax − Pmin) during idle. That admission is powerful § 103 fodder against claim 1, which adds only "an idle detection section" plus a comparator against "a predetermined amount of change."

4. Read the claims' scope carefully for non-infringement. Claim 1 recites detection of tubing disconnection keyed to an idle state and a ΔP "corresponding to a full open state of said throttle opening"; claim 2 limits the metric to the max-on-exhaust-stroke / min-on-intake-stroke differential pressure. Claim 5 adds the multi-sensor, one-per-cylinder substitution feature. Accused systems that estimate manifold pressure from a MAP/MAF model, or that lack per-cylinder dedicated pressure sensors with tubing, sit outside these limitations.

5. If a live PTAB proceeding does turn up on a re-run of E2E (or a just-filed petition the ODP feed hasn't ingested), treat it as a new item and report it — I'll pull the institution decision and FWD. As of this writing, the correct answer is: no PTAB activity on file, and the absence is compounded by expiration, which is itself the strongest defense signal available.

I'll verify the assignment records and check for any correspondent or litigation data before assembling the report.

Ownership Reconstruction — US 7,167,794 B2

Scope note / data caveat: I was not able to open assignmentcenter.uspto.gov directly in this session (no page returned for the reel/frame or correspondence queries). The reel/frame entries below are taken from the legal-events table on the patent record itself (Google Patents, https://patents.google.com/patent/US7167794/en), which mirrors the USPTO assignment index. Critically, that source does not expose the correspondent of record (the filing attorney/agent and their address), and I could not surface it by search. I flag that gap explicitly rather than guess — it blocks NPE signal #3 below.

Inventors

Pattern check:

• Single-inventor patent, so the "all inventors departed within 12 months" fire-sale tell is not applicable.
• The assignment was executed ~4 months after the JP priority filing (JP2005-114483, 2005-04-12) and ~1 month before the US filing (2005-08-31). This is a routine, near-contemporaneous employee-invention assignment to the employer — the classic profile of a captive corporate inventor, not an inventor-retained portfolio later sold off.
• No evidence of inventor departure, no assignment back to the inventor, no subsequent inventor-held entity. No unusual pattern.

Original assignee

Mitsubishi Denki Kabushiki Kaisha (rendered in English as Mitsubishi Electric Corporation), Tokyo, Japan.

• Business: Diversified electrical/electronics manufacturer. The subject matter (ECU controlling a V-type two-cylinder motorcycle engine via injector/ignition drives, with MAP-sensor diagnostics) sits in Mitsubishi Electric's automotive equipment line — engine-control components and ECUs supplied to vehicle makers, including the two-wheel segment.
• Product embodiment: Mitsubishi Electric's automotive-equipment division was a long-standing supplier of engine control units and powertrain electronics. The claims read on a production motorcycle ECU architecture of the type Mitsubishi Electric supplied, but I have no document in this record tying a specific shipping part number to this patent — treat "ships products embodying the claims" as consistent-with, not proven.
• Status: Operating. Not acquired, not dissolved, not in bankruptcy. In 2024 the automotive-equipment business was carved out into a wholly-owned subsidiary, Mitsubishi Electric Mobility Corporation (incorporated 2024-04-01, 100% owned by Mitsubishi Electric), which is the current recorded owner.
• Forward-looking (unverified news, flagged as such): press reports indicate Mitsubishi Electric has explored selling a ~50% stake in Mitsubishi Electric Mobility to Foxconn/Hon Hai, and that a lamp-systems JV with Stanley Electric was established via company split effective 2025-10-01. These are corporate-finance events, not patent-assertion events, and do not appear in the assignment index for this patent.

Assignment timeline

The index contains three recorded events for this patent. Only the first is an assignment of rights; the other two are corporate housekeeping/succession records.

• 2005-08-01 (executed) / recorded 2005-08-31 — Reel 016942/0265

  • Conveyance: Assignment (ASSIGNMENT OF ASSIGNOR'S INTEREST)
  • Assignor: Yousuke Fukuzawa (individual inventor)
  • Assignee: Mitsubishi Denki Kabushiki Kaisha
  • Correspondent: Not exposed in the available record — could not determine.
  • Context: Routine employee-invention assignment to employer at filing.

• effective 2005-11-07 / recorded 2024-09-03 — Reel 068829/0954

  • Conveyance: Change of Address (CHANGE OF ADDRESS)
  • Assignor: Mitsubishi Electric Corporation
  • Assignee: Mitsubishi Electric Corporation
  • Correspondent: Not exposed in the available record — could not determine.
  • Context: Pure housekeeping — same entity on both sides; updates the owner's recorded address. No change in beneficial ownership. (Note the ~19-year lag between effective date and recording date; this is a batch cleanup filing, not a transaction.)

• effective 2024-04-01 / recorded 2024-09-04 — Reel 068834/0585

  • Conveyance: Merger / Company Split (COMPANY SPLIT)
  • Assignor: Mitsubishi Electric Corporation
  • Assignee: Mitsubishi Electric Mobility Corporation
  • Correspondent: Not exposed in the available record — could not determine.
  • Context: Internal corporate reorganization — the automotive-equipment business (and the patents supporting it) was spun into a 100%-owned subsidiary. Not a sale to a third party, not a transfer to an asserter.

Correspondent recurrence check (signal #3): Cannot be run. None of the three entries surfaces the correspondent in the data I could retrieve. This is a genuine gap — I will not name an attorney or firm without a reel/frame citation.

Chain termination: The record ends at Mitsubishi Electric Mobility Corporation. No transfer to any licensing entity, no security agreement, no release, no license record.

Family context (same ownership across jurisdictions): US20060229798A1 (pre-grant pub), JP4335167B2, and DE102005047724B4 are family members sharing the JP2005-114483 priority. The German member shows as "Expired – Fee Related" and the US member as "Expired – Lifetime," with anticipated expiration 2025-08-31 (the 20-year term from the 2005-08-31 filing). The patent is now expired, which independently moots most assertion scenarios.

Timeline diagram

timeline
    title Ownership of US 7167794
    2005 : Inventor Fukuzawa assigns rights to Mitsubishi Denki
    2007 : US 7167794 B2 issued
    2024 : Change of address recorded for Mitsubishi Electric
         : Company split to Mitsubishi Electric Mobility
    2025 : Patent term expires

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. The only post-issuance transfer is Reel 068834/0585, a company split to Mitsubishi Electric Mobility Corporation, a 100%-owned subsidiary of the assignor. No "IP/Holdings/Ventures/Licensing" suffix, no registered-agent address, no single-member Delaware/Texas LLC. Contrast this with the classic shell-transfer pattern, which the record plainly does not exhibit.

2. Known asserter in the chain — NOT PRESENT. Neither Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Corporation, nor Mitsubishi Electric Mobility Corporation appears on any of the referenced NPE lists (Acacia, Marathon, IV, IPNav, Wi-LAN/Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, etc.). Searches for litigation naming US 7,167,794 returned no infringement suit; the only "Mitsubishi" litigation hits are unrelated antitrust/auto-parts matters and a Zond v. Fujitsu complaint concerning different patent numbers.

3. Repeat correspondent across the chain — UNKNOWN / NOT ASSESSABLE. This is the one signal I cannot rule in or out. The correspondent of record is not exposed in the legal-events data, and my search attempts did not retrieve it. No finding either way — three entries with (potentially) a single corporate-recording firm would be unremarkable for a Japanese multinational's housekeeping filings, but I have no reel/frame support, so I decline to characterize it.

4. Cascading transfers — NOT PRESENT. Exactly one substantive transfer in ~19 years (Reel 068834/0585), and it is an internal split, not a chained LLC cascade. No shared-correspondent, shared-address, or common-principal pattern to evaluate.

5. Pre-litigation transfer — NOT PRESENT. No infringement suit exists to be "within 6 months" of. The 2024 split was recorded ~2 years after the split's effective date and is unrelated to any assertion.

6. Bankruptcy fire-sale — NOT PRESENT. No Chapter 7/11, no receiver, no §363 sale. Mitsubishi Electric is a solvent, listed operating company (TSE: 6503).

7. Privateering — NOT PRESENT. No transfer to an NPE asserting on Mitsubishi Electric's behalf. The spin-out to Mitsubishi Electric Mobility is a captive subsidiary, not an assertion vehicle.

8. Defensive aggregator (anti-NPE) — NOT PRESENT. Chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at the original corporate family's automotive subsidiary.

Verdict

Insufficient data — but the deficiency runs only to assertion evidence, not to ownership. The record is actually strong enough to exclude an NPE conclusion: the only post-issuance transfer is Reel 068834/0585 (a 100%-owned company split to Mitsubishi Electric Mobility Corporation, effective 2024-04-01), preceded by the inventor's original assignment at Reel 016942/0265 and a same-party Change of Address at Reel 068829/0954. There is zero shell-entity, known-asserter, cascading-transfer, bankruptcy, privateering, or defensive-aggregator evidence, and no infringement suit naming this patent was found — so no NPE verdict (high or moderate) is supportable.

The reason I do not return "Operating-company" or "Defensive" instead is definitional: the patent has never been asserted by anyone (so it is not an operating-company assertion), and the chain does not terminate at a defensive aggregator (so it is not a defensive aggregation). Add that the patent expired 2025-08-31, and the realistic classification is "large-cap operating-company captive asset, now lapsed — not an NPE." The residual gap is the correspondent of record (signal #3), which the retrieved data does not expose.

Verify at: USPTO Patent Assignment Search — https://assignmentcenter.uspto.gov/ (search patent number 7,167,794); mirror index at https://assignment.uspto.gov/patent/index.html. Patent record: https://patents.google.com/patent/US7167794/en.

I'll research the patent citations for US 7,167,794 to assess their prior-art relevance.

Now let me research the Japanese and other cited references.

Prior-Art Analysis — US 7,167,794 B2

1. Patent under analysis (confirmed identity)

The claimed point of novelty is narrow: a failure-diagnosis section that, in the idle state, treats the within-one-control-cycle intake-pressure swing (ΔP = Pmax − Pmin over 720° CA) indicating a "full-open-throttle‑like" constant pressure as evidence of a tubing disconnection — as distinct from the conventional open/short-circuit detection of the sensor signal line.

2. References cited on the face of US 7,167,794 ("Patent Citations (3)")

These three references are the examiner-cited art of record and are the most probative.

2.1 US 4,483,299 A — the closest reference

• Full citation: US 4,483,299 A, "Method for detecting abnormality in sensor means for detecting a parameter relating to intake air quantity of an internal combustion engine," Honda Motor Co., Ltd. Priority 1982-08-12; issued 1984-11-20.
• Description: Stores the intake-pipe absolute-pressure sensor (PBA) output immediately after ignition-switch closure; compares the sensor output to that stored value; declares the sensor abnormal when the output remains substantially equal to the stored value for a predetermined time while the engine speed remains above a predetermined value. It expressly addresses the case where the pipe connecting the intake-pipe pressure sensor to the intake pipe "becomes disconnected," so the sensor reads atmospheric pressure constant regardless of actual intake-pipe pressure. Includes a fail-safe step substituting a stored value for the actual sensor output, and prohibits the abnormality determination in the fuel-cut/deceleration region.
• Elements it reaches relative to US 7,167,794: throttle-opening sensor (θTH sensor 4); intake-pressure sensor communicating with the intake pipe via a pipe (PBA 8); crank-angle/engine-speed sensing (Ne sensor 11, cylinder-discriminating sensor 12); an ECU (5); and — critically — tubing/pipe disconnection as the very abnormality being detected, with a fail-safe substitute signal.
• § 102 assessment: This is the single most relevant reference and the strongest § 102 candidate for claim 1, but on careful reading it does not anticipate claim 1 as a whole. US 4,483,299 detects disconnection by comparison to an ignition-ON-stored value, over time, above a speed threshold, and its inhibition condition is a deceleration/fuel-cut region — not an "idle detection section" nor the claimed criterion that "an amount of change of said intake pressure within one control period … indicates a predetermined amount of change corresponding to a full open state of said throttle opening." Claim 1 also requires detection of disconnection in addition to open/short-circuit detection of the signal line. US 4,483,299 is therefore best characterized as strong § 103 art (and a § 102 candidate only under an unduly broad reading of the determination clause). I flag this as a potential contradiction to any summary that treats US 4,483,299 as squarely anticipatory — it is close, not complete.

2.2 US 6,588,259 B2

• Full citation: US 6,588,259 B2, "Motorcycle having system for determining engine phase," Harley-Davidson Motor Company Group, Inc. (later assigned to Delphi Technologies). Priority 2000-07-20; filed 2002-11-05; issued 2003-07-08.
• Description: A V-twin motorcycle engine-phase determination system using a crank-gear/crankshaft-velocity sensor plus a pressure sensor on the air-intake manifold to determine engine phase at high rpm. Notes that where the engine has dedicated throttle bores per cylinder, a pressure sensor may be provided on each bore (or one on a single manifold), and the manifold-pressure value is used to identify which piston is on the intake stroke.
• Elements it reaches: the environmental/structural elements of claims 3 and 6 (V-type two-cylinder motorcycle) and, for claim 5, the notion of a pressure sensor per cylinder/bore. It contains no failure-diagnosis section and no tubing-disconnection detection.
• § 102 assessment: Anticipates no claim in full. It is relevant to the "V-type two-cylinder engine for a motorcycle" limitation of claims 3/6 and the per-cylinder sensor arrangement of claim 5; otherwise it is background art. Useful chiefly for § 103 combination.

2.3 JP 2002-295300 A — the acknowledged background reference ("first patent document")

• Full citation: JP 2002-295300 A, "Abnormality detection device for pressure sensor," Toyota Jidosha K.K. Filed/priority 2001-03-28; published 2002-10-09.
• Description: This is the reference the patent's own Background section cites as the conventional apparatus. Per the specification, it detects a signal-line abnormality (open-circuit or short-circuit) between the intake-pressure sensor and the control unit based on the amount of change of intake pressure, and when an abnormality is found the control unit inhibits use of that sensor's detection information.
• Elements it reaches: the "failure diagnosis section [that] detects an open-circuit or a short-circuit of a signal line … based on a change in said intake pressure" sub-limitation common to claims 1 and 5, and the inhibit-use concept later mirrored in claim 5's fail-safe.
• § 102 assessment: Anticipates neither claim 1 nor claim 5 as a whole — it lacks the tubing-disconnection detection that is the point of novelty of claim 1, and lacks the per-cylinder plural-sensor substitution of claim 5. It is nonetheless the most direct § 102 art for the open/short-circuit detection elements, and its two-stage characterization (signal-line fault vs. tubing fault) is exactly the gap the patent asserts.

3. Family-cited references (cited in the JP/DE family members; not on the US face)

These appear in the "Family Cites Families" list and were considered in the JP 2005-114483 / DE 10 2005 047 724 counterparts.

3.1 EP 0 581 151 A1

• Full citation: EP 0 581 151 A1, "Device for monitoring a sensor," Siemens Aktiengesellschaft. Priority 1992-07-22; published 1994-02-02.
• Description: A general sensor-monitoring device (monitoring a sensor output for plausibility/fault). Relevant only as generic sensor-diagnostic background.
• § 102 assessment: Anticipates no claim; general § 103 background.

3.2 JP 3136968 B2

• Full citation: JP 3136968 B2, "Intake pressure abnormality detection device for an internal combustion engine," Toyota Jidosha K.K. Filed 1995-10-20 (JP 07-272852; laid-open as JP H09-112316 A, 1997-04-28; also EP 0769612 B1); granted 2001-02-19.
• Description: Detects intake-pressure abnormality by learning the pressure-sensor detection value while the engine is in a predetermined steady operating state and comparing the learned value to the current detection value; if the difference exceeds a predetermined value, it judges an intake-pressure-related abnormality (including a sensor abnormality).
• Elements it reaches: intake-pressure abnormality detection in a steady state — conceptually adjacent to the "idle state" plausibility window of claim 1, but it uses a learned steady-state reference compared to the current value, not the within-720°-CA max−min differential.
• § 102 assessment: Anticipates no claim in full; relevant § 103 art on intake-pressure sensor fault detection.

3.3 JP 3741290 B2

• Full citation: JP 3741290 B2, "Pressure sensor fault diagnosis control device," Suzuki Motor Corp. Filed 1996-03-29; granted 2006-02-01 (the corresponding laid-open publication predates the critical date and is the actual § 102 art).
• Description: Fault-diagnosis control logic for a pressure sensor (as reflected in the family citation). Because only the granted date (2006-02-01) is shown, the on-sale/publication date of the underlying application must be verified before asserting it as § 102 art.
• § 102 assessment: Anticipates no claim in full; treat as § 103 background, subject to date verification.

3.4 KR 10-0428295 B1

• Full citation: KR 10-0428295 B1, "Apparatus for manifold air pressure sensor failure diagnosis on vehicle and method thereof," Hyundai Motor Co. Filed 2002-04-12; granted 2004-04-28.
• Description: Vehicle manifold-absolute-pressure (MAP) sensor failure diagnosis. Only the granted date and family record are available; the corresponding Korean laid-open publication would be the § 102 vehicle.
• § 102 assessment: Anticipates no claim in full; relevant § 103 art on MAP-sensor fault diagnosis. (My search step budget was exhausted before I could pull the KR full text — flag as not independently verified.)

4. Consolidated anticipation map

Bottom line: No cited reference anticipates any claim of US 7,167,794 under § 102. US 4,483,299 A is the most dangerous reference and is the primary § 103 combination candidate against claim 1 (its express recognition that a disconnected pressure-sensor pipe yields a constant atmospheric reading within a normal output range is squarely on the problem the patent claims to solve). US 6,588,259 B2 supplies the V-twin-motorcycle / per-cylinder-pressure-sensor environment for claims 3, 5, and 6, and JP 2002-295300 A supplies the admitted open/short-circuit diagnosis for claims 1 and 5.

5. Caveats

• Anticipation (US 4,483,299) is not clean. Its detection criterion differs from claim 1's "amount of change within one control period in the idle state indicating a predetermined amount of change corresponding to a full open state." I recommend framing it as § 103 art rather than § 102, and flag any contrary earlier summary as a contradiction.
• Dates for JP 3741290 B2 and KR 10-0428295 B1 are shown only as grant dates (2006-02-01 and 2004-04-28). Their § 102 status depends on the laid-open publication dates of the underlying applications, which I could not confirm before the search-step limit; the KR text was not independently retrieved (unverified).
• US 2015/0152802 A1 / US 9,810,171 B2 (Ford) appear only under "Cited By" (later art) and are not prior art to US 7,167,794; exclude them.
• DE 10 2005 047 724 is the German family member of this very invention (same priority), not prior art.
• I did not run a live USPTO Patent Center / Public Search API query in this session (search-step budget exhausted); the above relies on the Google Patents record plus the retrieved reference texts. A direct USPTO "Patent Application Full-Text" or patent-number lookup would close the verification gap on the JP/KR date questions.

I'll ground this obviousness analysis by first pulling details on the specific prior-art references cited on the patent's face.

Let me pull the remaining cited references: the Toyota pressure-sensor abnormality reference, the Suzuki and Hyundai diagnostics, and the Siemens monitoring device.

Obviousness Analysis — U.S. Patent No. 7,167,794 B2

"Control apparatus for an internal combustion engine" (Mitsubishi Denki K.K.; priority JP 2005-114483, 2005-04-12)

Scope note: This analysis uses only the references appearing in the "Prior Art" (Patent Citations / Family Cites Families) section of the patent page as supplied, plus their publicly available disclosures as retrieved in live search. All reference numbers are reproduced exactly as they appear; none have been auto-corrected. Where I could not verify a reference's full disclosure, I say so explicitly.

1. Framing

Under 35 U.S.C. § 103 and Graham v. John Deere, the question is whether the subject matter as a whole would have been obvious to a person of ordinary skill in the art (POSITA) at the 2005-04-12 priority date. Under KSR Int'l Co. v. Teleflex Inc. (2007), the analysis is expansive: a combination is obvious where (a) the prior art contains an express teaching, suggestion, or motivation to combine; (b) the combination is of known elements performing known functions with predictable results; (c) there is a design incentive or market pressure to solve the problem the patent addresses; or (d) there are a finite number of identified, predictable solutions — "obvious to try."

The invention in one sentence: In a control apparatus that already diagnoses an intake-pressure sensor's signal-line faults (open/short) from the amount of change of intake pressure, additionally diagnose a tubing/pipe disconnection fault by recognizing that, while the engine is idling, a disconnected tube makes the sensor read a near-constant atmospheric value — i.e., the pressure change over one 720° CA control cycle collapses to the value seen at wide-open throttle (Claims 1–2), warn the operator (Claim 4), and, where there are per-cylinder sensors, substitute a healthy sensor's reading for the failed one (Claim 5).

The critical observation for § 103 is that the single most on-point reference of record, US 4,483,299 (Honda), explicitly identifies and solves this exact problem.

2. The prior art of record — what each reference teaches

Not prior art (flag): US 2015/0152802 A1 / US 9,810,171 B2 (Ford, 2013-12-03, "Method for determining an offset of a manifold pressure sensor") appear on the page as Cited By, i.e., later documents citing this patent. They post-date the 2005-04-12 priority date and cannot be used in a § 103 combination against these claims.

3. Claim 1 — element-by-element mapping and combination

Claim 1 is the independent claim with the idle-detection + differential-pressure limitation. Every element is present in, or obvious over, the Honda + Toyota combination.

Combination 1 (primary): US 4,483,299 + JP 2002-295300 (optionally + JP 3136968 B2).

Motivation to combine — KSR factors:

1. The problem is expressly identified by the primary reference. Honda does not merely disclose an analogous feature; it names the precise failure mode the '794 patent claims to have newly solved — a disconnected sensor tube producing a constant atmospheric reading that falls inside the normal range. A POSITA seeking to improve a JP 2002-295300-style diagnostic, which the patent itself admits detects only signal-line faults, would look directly to Honda's teaching.
2. Known elements, known functions, predictable results. Each element (pressure sensor, throttle sensor, crank sensor, ECU, comparison of a pressure change against a threshold) is separately known; combining them produces nothing more than the predictable physical result that a disconnected tube reads atmospheric. There is no unexpected mechanism or result.
3. Finite, identified solutions / obvious to try. Once tubing disconnection is recognized as a plausible fault, the universe of detection techniques is small and predictable: (i) detect a constant reading while the engine runs (Honda); (ii) quantify the reading's change over the engine cycle and compare it to a threshold (the '794 approach). Choice (ii) is the natural refinement of (i) and is routine engineering.
4. Design incentive to gate on idle. Both Honda (prohibit determination during deceleration) and JP 3136968 (learn/compare only in a steady running condition, using an idle switch) teach suppressing the diagnostic outside operating regimes where false positives occur. Extending that known robustness gating to the idle condition — where intake manifold pulsation is greatest, as the '794 patent's own FIG. 2 concedes — is an obvious application of the prior art's own methodology, not invention.
5. Wide-open-throttle equivalence is inherent, not inventive. The claim's "predetermined amount of change corresponding to a full open state of said throttle opening" simply quantifies the well-known fact that an open throttle smooths manifold pressure. Honda already equates the disconnected reading with a normal range value; the '794 patent merely notes that the same flat trace appears at WOT (its own FIG. 3).

Conclusion — Claim 1 is obvious over US 4,483,299 in view of JP 2002-295300, further in view of JP 3136968 B2.

4. Claims 2–4

• Claim 2 (differential pressure between maximum intake pressure on the exhaust stroke and minimum intake pressure on the intake stroke as the "amount of change"). This is not a separate inventive step: it is the straightforward way to compute a cycle-based pressure swing with a crank-angle-resolved signal, and US 4,483,299 already uses the running engine and a sensor output that varies with manifold pressure to detect the constant/fault condition. Tracking min/max over a defined control period is a routine implementation choice (KSR: "a court must ask whether the improvement is more than the predictable use of prior art elements according to their established functions"). The patent's own FIG. 2 treats Pmax@exhaust / Pmin@intake as a known physical characteristic of a four-stroke engine, not a discovery. Obvious.

• Claim 3 (engine is a V-type two-cylinder engine for a motorcycle). US 6,588,259 B2 discloses exactly a motorcycle with a V-twin two-cylinder engine using intake-manifold pressure sensing. Combining Honda/Toyota diagnostics with the Harley V-twin motorcycle platform is a mere field-of-use/structural substitution with predictable results. Obvious. (Even standing alone, applying a known pressure-sensor diagnostic to a known V-twin motorcycle engine is not inventive.)

• Claim 4 (warning device driven on detection of tubing disconnection). The patent's own Background states that in conventional systems "the failure (i.e., abnormality in the signal line) is not displayed" — i.e., the deficiency is the absence of the warning, which the '794 patent cures by driving a lamp. Driving an indicator upon an already-detected fault is the paradigm of a predictable, non-inventive addition; the Background essentially concedes the motivation. Obvious. (Claim 7 is the same limitation appended to Claim 5 — same result.)

5. Claim 5 (second independent claim) — per-cylinder sensor substitution

Claim 5 shares the entire preamble and diagnosis limitations of Claim 1 (so all of Combination 1 above applies), and adds:

• a plurality of cylinders, with a plurality of intake pressure sensors corresponding in number to the cylinders measuring each cylinder's pressure individually; and
• when one sensor is abnormal, the control unit controls that cylinder using the intake pressure from a sensor determined normal.

Motivation: Redundancy substitution among multiple like sensors is a classic, predictable fail-safe measure, and the Honda reference already teaches the substitution concept (albeit with a stored fixed value). Using an actually-measured value from a sibling sensor on the same engine instead of a fixed stored value is a straightforward, obvious improvement — it is the same function (fail-safe continuation of engine control) performed by an equivalent, available element, with predictable results. A POSITA presented with a V-twin motorcycle engine carrying one pressure sensor per cylinder (Harley) and a diagnostic that condemns one sensor (Honda/Toyota) would readily continue operation on the remaining healthy sensor. Claim 5 is obvious.

Claims 6 and 7 (V-twin motorcycle engine; warning device) — obvious for the same reasons as Claims 3 and 4, respectively.

6. Anticipation check under § 102

US 4,483,299 is not, by itself, a § 102(b)/(a) anticipation of Claim 1, because it declares a fault when the output is constant for a predetermined period while speed is above a threshold, rather than when the amount of change within one 720° CA control period, in an idle state, equals the wide-open-throttle value. The claim's specific idle-gated, cycle-based metric is a narrowing difference that saves it from anticipation but not from § 103, for the reasons in § 3. (Note also that US 4,483,299 requires engine speed above a predetermined value, which reads against, rather than onto, the claim's idle condition — this difference is what the obvious combination argument above must, and does, bridge.)

7. Graham secondary considerations

• No unexpected results. The behavior of a disconnected tube (constant atmospheric output) is conceded by both Honda (1984) and the '794 patent itself. There is no teaching-away.
• Long-felt need / failure of others — weak to neutral. The patent's Background frames the gap as an unmet need, but Honda had expressly identified the same gap two decades earlier; the "need" here is the incremental diagnostics gap in one specific ECU, not a long-recognized, industry-wide failure.
• Foreign grant (JP 4335167 B2; DE 102005047724 B4) is not probative of US non-obviousness; examination outcomes in other jurisdictions are entitled to little or no weight, and the references of record were not shown to be identical to those considered elsewhere.
• Commercial success / copying / licensing: no evidence of record was located (consistent with the earlier litigation summary finding no known litigation involving US 7,167,794).

8. Bottom line

The strongest single sentence: The patent's own primary reference, US 4,483,299 (Honda), expressly describes the disconnected-pipe failure mode on which every independent claim depends and provides a fail-safe substitution remedy, while the admitted prior art JP 2002-295300 supplies the "diagnose from a change in intake pressure / inhibit use of the abnormal sensor" framework — leaving only routine, predictable implementation choices (cycle-based max/min metric, idle-state gating, an indicator lamp, and choosing one of several like sensors) to reach the claimed subject matter.

9. Confidence and gaps (stated explicitly)

• High confidence in the disclosures of US 4,483,299 A, JP 3136968 B2 (via JPH09112316A / EP 0 769 612 A2), and US 6,588,259 B2 — retrieved and quoted above.
• High confidence in the characterization of JP 2002-295300 A, but this rests on the patent's own Background statement (the patentee's admission) rather than a verified full-text translation of the Japanese document; I did not retrieve its complete disclosure.
• Lower confidence / not verified this session on the full disclosures of EP 0 581 151 A1, JP 3741290 B2, and KR 100428295 B1. I have treated them as cumulative to the Honda/Toyota diagnostics and flagged that reliance. A definitive § 103 opinion would require human English translations of these three documents in full.
• All Japanese/Korean-language references are cited by their listed titles/abstracts; I have not auto-adjusted any publication or patent number.
• No contradiction was found with the previously generated litigation section; the absence of litigation and of any secondary-considerations evidence is consistent with (and does not undermine) this obviousness conclusion.