P0A78
7 owner reports and 37 manufacturer filings across 18 model years from Cadillac, Chevrolet, Chrysler, Subaru and others.
Where P0A78 shows up
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports | Parts |
|---|---|---|---|---|
| 2024 Chrysler Pacifica | Electrical System | 4 | 2 | Battery → |
| 2021 Chrysler Pacifica | Electrical System | 4 | 2 | Battery → |
| 2023 Chrysler Pacifica | Electrical System | 4 | 1 | Battery → |
| 2025 Chrysler Pacifica | Electrical System | 3 | — | Battery → |
| 2022 Chrysler Pacifica | Electrical System | 3 | — | Battery → |
| 2020 Chrysler Pacifica | Electrical System | 3 | — | Battery → |
| 2019 Chrysler Pacifica | Electrical System | 3 | — | Battery → |
| 2017 Toyota Prius v | Electrical System | 3 | — | Battery → |
| 2016 Toyota Prius v | Electrical System | 3 | — | Battery → |
| 2024 Cadillac Lyriq | Fuel/Propulsion System | — | 1 | Fuel pump → |
| 2019 Chevrolet Bolt EV | Power Train | — | 1 | |
| 2025 Chrysler Voyager | Electrical System | 1 | — | Battery → |
| 2024 Chrysler Voyager | Electrical System | 1 | — | Battery → |
| 2023 Chrysler Voyager | Electrical System | 1 | — | Battery → |
| 2022 Chrysler Voyager | Electrical System | 1 | — | Battery → |
| 2021 Chrysler Voyager | Electrical System | 1 | — | Battery → |
| 2020 Chrysler Voyager | Electrical System | 1 | — | Battery → |
| 2016 Subaru Crosstrek | Engine | 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.
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P0A78 by make
The same record, one make at a time: the model years, bulletins and owner reports that name P0A78 on that maker’s vehicles.
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.
At approximately the time of the failure, Cadillac/OnStar Advanced Diagnostics generated a critical Electric Drive Unit warning instructing immediate service and reported diagnostic code P0A78
The vehicle is currently experiencing a recurring failure and is displaying active diagnostic trouble code P0A78 (Drive Motor "A" Inverter Performance), indicating a critical fault in the high-voltage hybrid propulsion system
I was able to connect with on star for live diagnostics showing a failure in the hybrid control processor (P0A78)
37 manufacturer filings name P0A78. Start with what the maker wrote down.
A code names the test that failed, not the part. A bulletin that names it is often a diagnosis someone has already written down — quote its number at the service desk.
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names P0A78.
- 9100801 Service bulletin2026-04-24 · Electrical System
- If the vehicle comes in with any of the following P codes, please refer to the active TSBs for HCP/AHCP flash BEFORE ordering PIM P0A78 - Drive Motor A Inverter Performance. P0A79 - Drive Motor B Inverter Performance. P0A3F-00 - Drive Motor A Position Sensor 1 Circuit. P0A43-00 - Drive Motor A Position Sensor Circuit Intermittent. P0A45-00 - Drive Motor B Position Sensor 1 Circuit. P0C1A-00 - Driv
- 9100801 Service bulletin2026-04-17 · Electrical System
- If the vehicle comes in with any of the following P codes, please refer to the active TSBs for HCP/AHCP flash BEFORE ordering PIM P0A78 - Drive Motor A Inverter Performance. P0A79 - Drive Motor B Inverter Performance. P0A3F-00 - Drive Motor A Position Sensor 1 Circuit. P0A43-00 - Drive Motor A Position Sensor Circuit Intermittent. P0A45-00 - Drive Motor B Position Sensor 1 Circuit. P0C1A-00 - Driv
- 08-253-24 Service bulletin2024-12-13 · Electrical System
- "Flash: Hybrid Control Processor (HCP) and Auxiliary Hybrid Control Processor (AHCP) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P0A78 - Drive Motor A Inverter Performance. ● P0A79 - Drive Motor B Inverter Performance.** ● P0A33 - Drive Motor B Temperature Sensor
- 08-209-24 Service bulletin2024-09-26 · Electrical System
- "Flash: Hybrid Control Processor (HCP) and Auxiliary Hybrid Control Processor (AHCP) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0A78 - Drive Motor A Inverter Performance. ● P0A79 - Drive Motor B Inverter Performance. Customers may also experience the following: ●
- 08-208-24 Service bulletin2024-09-26 · Electrical System
- "Flash: Hybrid Control Processor (HCP) and Auxiliary Hybrid Control Processor (AHCP) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0A78 - Drive Motor A Inverter Performance. ● P0A79 - Drive Motor B Inverter Performance. Customers may also experience the following: ●
- 23TE02 Service bulletin2023-06-07 · Electrical System
- DP: The Customer Confidence Program is a component of a class action settlement that includes several elements of coverage. The Customer Confidence Program provides coverage as it applies to the intelligent power module (IPM). The specific condition covered by this Customer Confidence Program 23TE02 is failure of the IPM located inside the inverter assembly of the hybrid system indicated by DTCs P
What P0A78 means
Source: SAE J2012 / OBD-IIP0A78 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 P0A78
Source: NHTSA files and the OBD-II standardCan I keep driving with P0A78 stored?
Nobody can answer that from the code alone, and a site that does is guessing. A steady light means a fault was logged and the car should be checked soon; a flashing light means a severe misfire — slow down and get it seen as soon as possible, because severe misfire can quickly damage the catalytic converter. 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.