Powertrain
generic / SAE
P0891
TCM Power Relay Sense Circuit High
The TCM detects voltage on the relay sense line above threshold while relay is commanded open, indicating relay welded closed or short to power.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number8 / 91
Possible causes
- Relay contacts welded high
- Wiring shorted to battery medium
- Connector pins corroded - high contact resistance low
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 80–400 €
- Estimated time: 0.5–2.5 h
- Component: tcm relay
- Component: wiring harness
- MIL / check engine light
Sources
References
sae:J2012