DTC Troubleshooting: P1658 (40)
DTC P1658:
 Electronic Throttle Control System (ETCS) Control Relay ON Malfunction
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
  1. Turn the ignition switch to ON (II).
  1. Do the ETCS TEST in the INSPECTION MENU with the HDS.
Is the RELAY circuit OK?
YES -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the under-hood fuse/relay box and the ECM.■
NO -
Go to Step 3 .
  1. Turn the ignition switch to LOCK (0).
  1. Test the ETCS control relay in the under-hood fuse/relay box.
Is the relay OK?
YES -
Go to Step 5 .
NO -
Replace the under-hood fuse/relay box, then go to Step 15 .
  1. Jump the SCS line with the HDS.
  1. Disconnect under-hood fuse/relay box (white) connector D (20P).
  1. Disconnect ECM connector A (49P).
  1. Check for continuity between ECM connector terminal A21 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM (A21) and the under-hood fuse/relay box, then go to Step 15 .
NO -
Go to Step 9 .
  1. Disconnect ECM connector C (49P).
  1. Reconnect under-hood fuse/relay box (white) connector D (20P).
  1. Turn the ignition switch to ON (II).