DTC code
P0887
TCM Power Relay Control Circuit High
Technical guide
Symptoms
- Check engine light or stored fault in the affected control module
- transmission shifts much more harshly than normal or will not shift at all
- transmission may remain in limp mode
- which can effectively immobilize the vehicle
- traction control or ABS lights may come on with those systems disabled.
Probable causes
1) Defective TCM power relay (defective contact relay). 2) Blown fuse or burnt fusible link. 3) Damaged wiring or connectors in the relay control circuit (cut, burned, or damaged wiring). 4) High voltage output from the alternator or battery. 5) Failed or failing Transmission Control Module.
Diagnostic steps
- Connect a diagnostic scanner, record codes and freeze frame; have a digital volt/ohmmeter (DVOM) and vehicle-specific wiring information available.
- Perform a visual inspection of the relay, related wiring and connectors; repair or replace wiring that is cut, burned, or damaged.
- Check the TCM power relay fuse and any fusible links; replace blown fuses.
- Use the DVOM to test voltage and ground circuits at the TCM and/or PCM; if no voltage is detected, test the system relay and related fuses, replacing defective relays as required.
- Verify charging system output is within specification to rule out alternator/battery overvoltage.
- If the relay, fuses, wiring, and supply voltages all test good, suspect the TCM/PCM and diagnose per the factory procedure.
- Clear the code and road test to confirm the repair.
Cross-checked technical synthesis (QA). It does not replace the manufacturer's procedure.
Models most reported with this code (NHTSA)
Count of distinct owner complaints mentioning the code. US data — same engines, same failures.
AI here is a librarian: this page shows only what mechanics confirmed, or says “unknown”. It never suggests a diagnosis — MECCANIC interprets the code, never your car.
0 confirmed cases on P0887
Nothing confirmed yet for this code. No guess is offered on purpose.
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