When you go to start your vehicle, TCM does a self check to see if there is enough juice from the battery to operate itself. If there is a low voltage signal on the power relay control circuit, a P0886 DTC will be stored in the ECU memory.
What Transmission Do I Have?
How Serious is the Code?
The P0886 diagnostic trouble code is pretty serious as OBD2 codes go. It basically means that there isn’t enough power to operate the transmission control module, which can lead to a number of issues including rough shifts and engine stalling.
Symptoms
Symptoms of a P0886 include:
- Rough shifting
- Delayed shifts
- Erratic transmission behavior
- Engine may shut off an expectedly
- Shift interlock failure
- Speedometer malfunction
Causes
- Faulty TCM power relay
- Blown fuse
- Defective fusible link
- Wiring or connectors problems
- ECU programming/function problem
How to Diagnose the Code?
The first step to properly diagnose a P0886 OBDII trouble code, is to check the battery voltage to see if it is putting out enough power. If the battery or the alternator fail, they should be replaced. The fuses, relays and fusible links should also be checked for proper operation. If everything checks out by this point, then the wiring and connectors should all be checked. If there is power going to the power relay connector, the problem could be with either the ECU or its software version. If there is no power going to the TCM power relay connector, then the problem lies somewhere in the wiring or relays/fuses.
What Transmission Do I Have?
What Repairs Will Fix P0886?
- Repair or replace damaged wiring/connectors
- Replace the power relay
- Replace the blown fuse(s)
- Replace the fusible link
- Reprogram or replace the ECU
Related Codes
- P0700 – Transmission Control System Malfunction
- P0701 – Transmission Control System Range/Performance
- P0702 – Transmission Control System Electrical
- P0800 – TCM Power Input Signal Malfunction
