P0886: Transmission Control Module Power Relay Control Circuit Low
What to do
Watch for the battery going flat if the car stands for a few days — that is this fault rather than a failing battery, and replacing the battery will not fix it.
What this code means
The relay control circuit is held low, normally a short to ground, which generally leaves the relay energised whether or not the module wants it. The consequence is the battery-drain half of the P0885 pair: the module never fully powers down and continues drawing current with the vehicle parked.
Likely causes
Start here
- Wiring shorted to ground · moderate
- Faulty transmission control module power relay · easy
Less common
- Corroded or loose connector · easy
Rare
- Faulty transmission control module · specialist
Symptoms
Components involved
Information, not instruction
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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.
Community experience
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