Error code

OBD2 P0888

OBD2P0888
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

TCM Power Relay Sense Circuit.

Severity

moderateThe vehicle can be driven but may experience limited functionality and safety issues.

Summary

Code P0888 indicates an issue with the transmission control module's power relay sense circuit, which is responsible for controlling the transmission solenoid pack.

Symptoms

  • Illuminated check engine light
  • Vehicle stuck in 'limp' mode
  • Transmission not shifting

Common Causes

  • Wiring problems
  • Failed transmission control relay
  • Faulty TCM or TCM programming

Diagnosis

  1. Inspect the transmission control relay for corrosion, burnt terminals, etc.
  2. Check technical service bulletins (TSBs) related to the issue
  3. Test the relay by jumping the primary circuit and checking secondary side continuity
  4. Verify power and ground sides of the circuit using a test light
  5. Check the TCM's command to the relay for proper voltage

Fixes

  • Replace faulty transmission control relay

FAQ

What should I do if my car is stuck in 'limp' mode?

First, inspect the transmission control relay and its wiring. If issues are found, repair or replace them as needed.

How can I check for continuity between TCM and TCR?

Use a digital multimeter set to ohms to measure continuity between the TCM's relay control terminal and the relay control terminal in the fuse box.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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