Cause
Faulty transmission control module
The computer that decides gear changes and drives the solenoids. It is named by many codes and is genuinely at fault in very few of them.
Its supply, earth and connector come first, and a replacement normally has to be programmed to the vehicle — so a wrong diagnosis here costs considerably more than the part.
Typically specialist work. Needs equipment or training most home workshops do not have.
Some of these codes mean you should stop driving
5 of the 364 codes this can cause indicate a fault where continuing to drive risks damage or is unsafe. Which one you have matters more than the cause does — read the code's own page before deciding.
Codes this can cause (364)
Codes where this is a likely explanation first, rather than merely a possible one.
- P0613 Transmission Control Module Processor Likely for this code High
- P0700 Transmission Control System (Malfunction Indicator Lamp Request) Likely for this code Moderate
- P0702 Transmission Control System Electrical High
- P0727 Engine Speed Input Circuit No Signal High
- P0737 Transmission Control Module Engine Speed Output Circuit Moderate
- P0738 Transmission Control Module Engine Speed Output Circuit Low Moderate
- P0739 Transmission Control Module Engine Speed Output Circuit High Moderate
- P0768 Shift Solenoid D Electrical High
- P0813 Reverse Output Circuit Moderate
- P0863 Transmission Control Module Communication Circuit High
- P0864 Transmission Control Module Communication Circuit Range/Performance High
- P0865 Transmission Control Module Communication Circuit Low High
- P0866 Transmission Control Module Communication Circuit High High
- P0898 Transmission Control System Malfunction Indicator Lamp Request Circuit Low Moderate
- P0899 Transmission Control System Malfunction Indicator Lamp Request Circuit High Moderate
- P0960 Pressure Control Solenoid A Control Circuit/Open High
- P0961 Pressure Control Solenoid A Control Circuit Range/Performance High
- P0962 Pressure Control Solenoid A Control Circuit Low High
- P0965 Pressure Control Solenoid B Control Circuit Range/Performance High
- P0966 Pressure Control Solenoid B Control Circuit Low High
- P0969 Pressure Control Solenoid C Control Circuit Range/Performance High
- P0970 Pressure Control Solenoid C Control Circuit Low High
- P0973 Shift Solenoid A Control Circuit Low High
- P0976 Shift Solenoid B Control Circuit Low High
- P0979 Shift Solenoid C Control Circuit Low High
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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