DTC Troubleshooting: P1659 (40)
DTC P1659:
 Electronic Throttle Control System (ETCS) Control Relay OFF 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. Clear the DTC with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1659 indicated?
YES -
Go to Step 4 .
NO -
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.■
  1. Turn the ignition switch to LOCK (0).
  1. Check the No. 8 DBW (THROTTLE ACTUATOR CONTROL) (15 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES -
Go to Step 6 .
NO -
Go to Step 13 .
Is the relay OK?
YES -
Go to Step 7 .
NO -
  1. Jump the SCS line with the HDS.
  1. Disconnect under-hood fuse/relay box (white) connector D (20P).
  1. Disconnect ECM connector C (49P).
  1. Check for continuity between under-hood fuse/relay box connector D (20P) terminal No. 6 and ECM connector terminal C1.
Is there continuity?
YES -
Go to Step 11 .
NO -
Repair open in the wire between the ECM (C1) and the under-hood fuse/relay box, then go to Step 21 .
  1. Disconnect ECM connector A (49P).
  1. Check for continuity between under-hood fuse/relay box connector D (20P) terminal No. 17 and ECM connector terminal A21.
Is there continuity?
YES -
Go to Step 26 .
NO -
Repair open in the wire between the ECM (A21) and the under-hood fuse/relay box, then go to Step 21 .
  1. Jump the SCS line with the HDS.
  1. Disconnect under-hood fuse/relay box connector D (20P).
  1. Disconnect ECM connector C (49P).
  1. Check for continuity between ECM connector terminal C1 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM (C1) and the under-hood fuse/relay box, then go to Step 21 .
NO -
Go to Step 17 .
  1. Install the under-hood fuse/relay box, and replace the No. 18 DBW (THROTTLE ACTUATOR CONTROL) (15 A) fuse.
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between ECM connector terminal C1 and body ground.
Is there battery voltage?
YES -
Go to Step 26 .
NO -
Replace the under-hood fuse/relay box. Also replace the No. 18 DBW (THROTTLE ACTUATOR CONTROL) (15 A) fuse, then go to Step 21 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect all connectors.
  1. Turn the ignition switch to ON (II).
  1. Reset the ECM with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1659 indicated?
YES -
Check for poor connections or loose terminals at the under-hood fuse/relay box and the ECM, 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. Reconnect all connectors.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1659 indicated?
YES -
Check for poor connections or loose terminals at the under-hood fuse/relay box and the ECM. If the ECM was updated, substitute a known-good ECM, then recheck. If the ECM was substituted, go to Step 1 .
NO -
If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■