P0C78
0 owner reports and 19 manufacturer filings across 7 model years from Chevrolet, Ford.
Where P0C78 shows up
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports | Parts |
|---|---|---|---|---|
| 2022 Ford Mustang Mach-E | Electrical System | 5 | — | Battery → |
| 2021 Ford Mustang Mach-E | Electrical System | 5 | — | Battery → |
| 2019 Chevrolet Bolt EV | Electrical System | 2 | — | Battery → |
| 2018 Chevrolet Bolt EV | Electrical System | 2 | — | Battery → |
| 2017 Chevrolet Bolt EV | Electrical System | 2 | — | Battery → |
| 2023 Ford Mustang Mach-E | Electrical System | 2 | — | Battery → |
| 2016 Chevrolet Spark | 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.
Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
What it gets filed under
19 manufacturer filings name P0C78. 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 P0C78.
- TSB 23-2348 Service bulletin2023-11-10 · Electrical System
- This article supersedes TSB 23-2257 to update the Parts List. Some 2021-2023 Mustang Mach-E vehicles built on or before 17-Mar-2023 may exhibit an illuminated malfunction indicator lamp (MIL) and/or powertrain malfunction (wrench) indicator with diagnostic trouble codes (DTCs) P0563, P0ADA, P0ADE, P0AA1, P0AA4, P0AA5, P0AA2, P0D10, P0D0F, and/or P0C78 stored in battery energy control module (BECM)
- TSB 23-2257 Service bulletin2023-08-22 · Electrical System
- Some 2021-2022 Mustang Mach-E vehicles built on or before 17-Mar-2023 may exhibit an illuminated malfunction indicator lamp (MIL) and/or powertrain malfunction (wrench) indicator with diagnostic trouble codes (DTCs) P0563, P0ADA, P0ADE, P0AA1, P0AA4, P0AA5, P0AA2, P0D10, P0D0F, and/or P0C78 stored in battery energy control module (BECM). It may also have a low/discharged 12V battery and/or display
- TSB 22-2178 Service bulletin2022-08-02 · Electrical System
- Some 2021-2022 Mustang Mach-E vehicles built on or before 28-May-2022 may exhibit an illuminated malfunction indicator lamp (MIL) and/or display a Stop Safely Now message in the instrument panel cluster (IPC) with diagnostic trouble codes (DTCs) P0563, P0ADA, P0ADE, P0AA1, P0AA4, P0AA5, P0AA2, P0D10, P0D0F, and/or P0C78 stored in battery energy control module (BECM) or a low/discharged 12V battery
- 18NA225 Service bulletin2020-09-23 · Engine And Engine Cooling
- This technical bulletin provides information to diagnose a MIL Illuminated with Loss of Propulsion and one or more of the following DTCs Set: P0ABC, P0AFA, P1AE6, P0D26, P0C78, P0ABB.
- 18NA225 Service bulletin2019-08-08 · Electrical System
- This Bulletin provides information to diagnose a MIL Illuminated with Loss of Propulsion and one or more of the following DTCs P0ABC, P0AFA, P1AE6, P0D26, P0C78, P0ABB Set.
- 16-NA-072 Service bulletin2016-03-07 · Engine And Engine Cooling
- This technical bulletin provides a proedure to replace the heater coolant heater for vehicles with the condition of No Start along with DTC P0C78
What P0C78 means
Source: SAE J2012 / OBD-IIP0C78 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 P0C78
Source: NHTSA files and the OBD-II standardCan I keep driving with P0C78 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.