P0AC4
6 owner reports and 8 manufacturer filings across 5 model years from Cadillac, Chevrolet.
Where P0AC4 shows up
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2017 Chevrolet Volt | Fuel/Propulsion System | 2 | 2 |
| 2016 Chevrolet Volt | Equipment | 3 | 1 |
| 2018 Chevrolet Volt | Electrical System | 1 | 2 |
| 2016 Cadillac ELR | Power Train | 2 | — |
| 2019 Chevrolet Volt | Electrical System | — | 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.
Below is a list of all the CEL codes that were pulled: P06DB P0030 P0031 P0403 P0405 P0443 P0458 P0489 P0597 P0598 P06DA P0AC4 P0135 P0AC4 P16E0 Looking into this issue I found that this is an one of the most common failures in the Chevy…
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names P0AC4. Quoting the document number at a service desk is often the fastest route to a diagnosis someone has already written down.
- PIP5202C2020-05-06 · Electrical System
- This Preliminary Information communication provides information to the technician the steps to diagnose and repair vehicles that have Check Engine Light illuminated with an "Engine Unavailable" and "Reduced Propulsion" messages on the Driver Information Center. Technician may find Diagnostic Trouble Codes a P0AB9 and P0AC4. Technician should not clear any Diagnostic Trouble Codes and ensure Global
- PIP5202B2019-04-15 · Power Train
- This Preliminary Information communication provides information to the technician the steps to diagnose and repair vehicles that have Check Engine Light illuminated with an "Engine Unavailable" and ?Reduced Propulsion? messages on the Driver Information Center. Technician may find Diagnostic Trouble Codes a P0AB9 and P0AC4. Technician should not clear any Diagnostic Trouble Codes and ensure Global
- 18NA0162018-01-18 · Electrical System
- This Bulletin provides ECM reprogramming information to Correct DTC P3260 and P0AC4.
- PIC62942017-07-26 · Equipment — Other — Owners/Service/Other Manual
- This Preliminary information communicates to dealers on how to diagnose and repair the vehicle if it setsDiagnostic trouble codes P0AC4 (ECM) and P2797 (HPCM)
- GCUS-3-6202016-07-15 · Power Train — Automatic Transmission — Control Module (Tcm/Pcm/Tecm)
- 27660 - Service Update. The engine may stall, followed by a Driver Information Center (DIC) message ?Action Required-Engine Not Available?. This will also cause diagnostic trouble codes P0AB9 (Hybrid/EV System Performance) and P0AC4 (Hybrid/EV Powertrain Control Module Requested MIL Illumination) to set. The engine will not start until the key is cycled. Dealers will reprogram the drive motor
What P0AC4 means
Source: SAE J2012 / OBD-IIP0AC4 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 P0AC4
Source: NHTSA files and the OBD-II standardCan I keep driving with P0AC4 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.