Traction Control System

TCS DTC 31: Engine Retard Command (PFINH) signal

NOTE: If the MIL or ABS indicator is ON, troubleshoot the PGM-FI or ABS first.

1. Disconnect PCM connector E (20P) and ABS/TCS control unit connector B(16P).





2. Check for continuity between PCM connector E (20P) terminal No. 7 and body ground.
Is there continuity?
YES-Repair short to body ground in the wire between the PCM and the ABS/TCS control unit.
NO-Go to step 3.





3. Measure the voltage between the PCM connector E (20P) terminal No. 7 and body ground.
Is there more than 1 V ?
YES-Repair short to power in the wire between the PCM and the ABS/TCS control unit.
NO-Go to step 4.
4. Connect PCM connector E (20P).
5. Start the engine.








6. Measure the voltage between PCM connector E (20P) terminal No. 7 and body ground.

NOTE: Use the 10 V range or similar range in an analog tester.

Is there about 2.5 V?
YES-Go to step 7.
NO-Check for loose PCM connectors. If necessary, substitute a known-good PCM, and recheck.








7. With an analog voltmeter set to the 10 V or similar range, measure the voltage between ABS/TCS control unit connector B (16P) terminal No. 10 and body ground.
Is there about 2.5 V?
YES-Check for loose ABS/TCS control unit connectors. If necessary, substitute a known-good ABS/TCS control unit, and recheck.
NO-Repair open in the wire between the PCM and the ABS/TCS control unit.