DTC Troubleshooting: P1658 (40)
  1. Check for continuity between ECM/PCM connector terminal A21 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM/PCM (A21) and the ETCS control relay, then go to Step 13 .
NO -
Go to Step 9 .
  1. Disconnect ECM/PCM connector C (49P).
  1. Turn the ignition switch to ON (II).