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 ON (II).
  1. Do the ETCS TEST in the INSPECTION MENU with the HDS.
Is the RELAY normal?
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 OFF.
  1. Test the ETCS control relay in the under-hood fuse/relay box.
Is the ETCS control relay OK?
YES -
Go to Step 5 .
NO -
Replace the under-hood fuse/relay box, then go to Step 15 .
  1. Remove the battery.
  1. Disconnect under-hood fuse/relay box connector D (20P).
  1. Disconnect ECM connector A (44P).
  1. Check for continuity between ECM connector terminal A20 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM (A20) and the under-hood fuse/relay box, then go to Step 15 .
NO -
Go to Step 9 .
  1. Disconnect ECM connector C (44P).
  1. Reconnect under-hood fuse/relay box connector D (20P).
  1. Connect a battery.
  1. Turn the ignition switch ON (II).