P0888TCM Power Relay Sense Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Some gearboxes draw their power through a relay, such as the transmission control relay in Chrysler's fuse box that feeds the solenoids. P0885 to P0887 cover the coil control of that relay, P0888 to P0892 its sense line, which reads back the switched output and compares it with the command. A dead relay leaves all solenoids without power, so the gearbox drops into its hydraulic emergency gear. P0888 is the general fault of the sense line, without telling low, high or range apart. No maker documents it on its own; Subaru uses the low variant P0890.
- What you may notice
- MIL on
- Limp mode in a fixed gear, no shifting
- Harsh engagement into D or R
- Likely causes
- LikelyRelay contacts burnt or corroded
- PossibleFuse in the load circuit
- PossibleWire between relay output and module
- RareModule
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €20 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.