P1656

DTC P1656: Problem in PCM-to-VSA Control Unit Communications Circuit

NOTE: Record all freeze data and review General Troubleshooting Information before you troubleshoot.

1. Turn the ignition switch OFF.
2. Disconnect PCM connector A (32P) and VSA control unit connector C (26P).





3. Check for continuity between PCM connector terminal A22 and VSA control unit connector terminal C10.
Is there continuity?
YES - Go to step 4.
NO - Repair open in the wire between PCM connector terminal A22 and VSA control unit connector terminal C10.





4. Check for continuity between VSA control unit connector terminal C10 and body ground.
Is there continuity?
YES - Repair short to ground in the wire between PCM connector terminal A22 and VSA control unit connector terminal C10.
NO - Go to step 5.
5. Connect PCM connector A (32P).
6. Turn the ignition switch ON (II).





7. Check for voltage between PCM connector terminal A22 and body ground.
Is there about 10 V?
YES - Check for loose terminal fit in PCM connector A22 and VSA control unit connector C10. If necessary, substitute a known-good PCM and recheck.
NO - Replace the PCM.