U0129
4 owner reports and 13 manufacturer filings across 10 model years from BMW, Chevrolet, GMC, Honda and others.
Where U0129 shows up
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2020 GMC Sierra | Engine And Engine Cooling | 4 | — |
| 2026 Jeep Grand Cherokee | Power Train | 3 | — |
| 2025 Jeep Grand Cherokee | Power Train | 3 | — |
| 2022 BMW X3 | Service Brakes | — | 1 |
| 2023 Chevrolet Malibu | Power Train | — | 1 |
| 2017 Honda CR-V | Fuel/Propulsion System | — | 1 |
| 2025 Jeep Grand Wagoneer | Power Train | 1 | — |
| 2024 Jeep Grand Wagoneer | Power Train | 1 | — |
| 2025 Jeep Wagoneer | Power Train | 1 | — |
| 2017 Toyota Corolla | Service Brakes | — | 1 |
A model year appears here because the code is named in its record, not because every one of these vehicles sets it. Counts are mentions in the federal files, not failure rates — nobody publishes the denominator.
What it gets filed under
What owners said
Source: NHTSA complaint databaseOwners’ own words, one per nameplate, scrubbed of anything identifying. These are unverified reports filed with NHTSA — they are what was said, not a finding that it was true.
The diagnostic machine retrieved DTC: U0073, P0700, P25A2, U0101,U0129,U0146, U18D5, U18D7, U2413, U0073-00, U0100-00, U0140-00, U0151-00, U026A-00, U0420-00 and U0100
Car is at Honda now 1/10/20, they are stating all codes may be due to two codes that need to be fixed: P0302 (fuel injection), which is covered under warranty and U0129 lost communication with braking system due to A/C control unit - which…
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names U0129. Quoting the document number at a service desk is often the fastest route to a diagnosis someone has already written down.
- 91006412025-08-05 · Power Train
- Symptoms/Condition: Shifter reports loss communication AND NO OTHER MODULES report the condition. Diagnostic: Please make sure ONLY shifter reports loss communication. If there are other modules reporting loss communication, then follow the existing service procedure Repair Procedure: 1. Verify Complaint - ESM reports a Loss of Communication (LOC) DTC, but no other modules do. - If multiple module
- PIT5713A2020-12-22 · Lane Departure
- This Preliminary information communicates an issue with the engine wiring harness shorting at the left front cylinder head causing any of the following issues: - IPC gauges sweeping while driving - Several IPC warning messages and MIL displayed - Any combination of the following DTC's: U0073 U0100 U0101 U0121 U0128 U0129 U0131 U0140 U0146 U0422 U2413 P0107 P0117 P0119 P0641 C2A07
- PIT5713A2020-05-07 · Engine And Engine Cooling
- This Preliminary information communicates an issue with the engine wiring harness shorting at the left front cylinder head causing any of the following issues: - IPC gauges sweeping while driving - Several IPC warning messages and MIL displayed - Any combination of the following DTC's: U0073 U0100 U0101 U0121 U0128 U0129 U0131 U0140 U0146 U0422 U2413 P0107 P0117 P0119 P0641 C2A07
- PIT57132019-09-30 · Engine And Engine Cooling
- This Preliminary information communicates an issue with the engine wiring harness shorting at the left front cylinder head causing any of the following issues: - IPC gauges sweeping while driving - Several IPC warning messages and MIL displayed - Any combination of the following DTC's: U0073 U0100 u0101 u0121 u0128 U0129 u0131 U0140 U0146 U0422 U2413 P0107 P0641 C2A07
What U0129 means
Source: SAE J2012 / OBD-IIU0129 sits in the generic range of the OBD-II standard, so it means the same thing on every vehicle sold in the United States — but WhichTrim does not carry a definition for it and will not invent one. What is on this page is the record: who named it and on what.
A stored code names the test that failed, never the part that caused it. It is the starting point of a diagnosis, not its conclusion — the same code has several possible causes and the cheap one is not always right.
Common questions about U0129
Source: NHTSA files and the OBD-II standardCan I keep driving with U0129 stored?
Nobody can answer that from the code alone, and a site that does is guessing. A steady light generally means the fault was logged and the vehicle is in a reduced-risk mode; a flashing light means stop soon, because a misfiring engine can destroy a catalytic converter in minutes. The safe read of this page is the mileage and the components, not permission.
Does a code mean the car is recalled?
No. Recalls are filed by campaign and matched by VIN, and none of them are triggered by a scan tool. If you want to know whether an open recall applies to one specific vehicle, check the VIN at nhtsa.gov/recalls — that is the only source that settles it.
Why do the counts here differ from other sites?
Because these are not estimates. Every number on this page is a count of documents in NHTSA's own files: manufacturer communications that name the code in their filed summary, and owner complaints that name it in the narrative. We do not model, weight or extrapolate them.
Will clearing the code fix it?
Clearing turns the light off and erases the freeze-frame data a technician would have used to work out what happened. If the condition is still there the code returns, usually within a few drive cycles, and the diagnosis now starts from less information than before.