P0891
PowertrainTransmissionhigh severityTCM Power Relay Sense Circuit Signal Stuck Off
What P0891 Means
The transmission control module sees the power relay sense signal stuck in the off state. The relay is not energizing when commanded on.
Symptoms
- Transmission warning light on
- Transmission enters limp mode
- No shifting response
Common Causes
- Faulty TCM power relay
- Open circuit in sense wiring
- Corroded or loose connectors
- Faulty transmission control module
Diagnostic Steps
- Scan for related transmission codes
- Test relay energizing operation
- Check sense circuit for open
- Inspect connectors and wiring
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