P0888
TCM Power Relay Sense Circuit
The TCM power relay reports a sense circuit condition. TCM supply control is impaired.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
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
Common causes
Ordered by how often each turns out to be the cause.
- Feedback wire faultCommon
- Relay contact agedPossible
Parts involved
- TCM Power Relay
- Wiring Harness
- TCM
P0888 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.