( TF09EABK72100091658FAAT00 )
DTC Troubleshooting: P1658 (40)
DTC P1658:
 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 ETCS control relay and the ECM/PCM.■
NO -
Go to Step 3 .
  1. Turn the ignition switch to LOCK (0).
  1. Open the fuse lid (A), then remove the ETCS control relay (B) from the under-dash fuse/relay box.
Is the ETCS control relay OK?
YES -
Go to Step 6 .
NO -
Replace the ETCS control relay, then go to Step 13 .
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM/PCM connector A (49P).
  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).
  1. Measure the voltage between ECM/PCM connector terminal C1 and body ground.
Is there battery voltage?
YES -
Repair short to power in the wire between the ECM/PCM (C1) and the ETCS control relay, then go to Step 12 .
NO -
Go to Step 18 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect all connectors.
  1. Turn the ignition switch to ON (II).
  1. Reset the ECM/PCM with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1658 indicated?
YES -
Check for poor connections or loose terminals at the ETCS control relay and the ECM/PCM, then go to Step 1 .
NO -
Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect all connectors.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1658 indicated?
YES -
Check for poor connections or loose terminals at the ETCS control relay and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then recheck. If the ECM/PCM was substituted, go to Step 1 .
NO -
If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■