( TF09EACK72100091659FAAT00 )
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 ETCS control relay and the ECM/PCM.■
  1. Turn the ignition switch to LOCK (0).
  1. Check the No. 52 ETCS (15 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES -
Go to Step 6 .
NO -
Go to Step 19 .
  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 8 .
NO -
Replace the ETCS control relay, then go to Step 25 .
  1. Turn the ignition switch to ON (II).
RHD model
LHD model
  1. Measure the voltage between ETCS control relay 4P connector terminal No. 3 and body ground.
Is there battery voltage?
YES -
Go to Step 10 .
NO -
Replace the under-dash fuse/relay box, then go to Step 24 .
  1. Measure the voltage between ETCS control relay 4P connector terminal No. 2 and body ground.
Is there battery voltage?
YES -
Go to Step 11 .
NO -
Replace the under-dash fuse/relay box, then go to Step 24 .
  1. Turn the ignition switch to LOCK (0).
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM/PCM connector C (49P).
  1. Connect ETCS control relay 4P connector terminal No. 1 to body ground with the jumper wire.
  1. Check for continuity between ECM/PCM connector terminal C1 and body ground.
Is there continuity?
YES -
Go to Step 16 .
NO -
Repair open in the wire between the ECM/PCM (C1) and the ETCS control relay, then go to Step 25 .
  1. Disconnect ECM/PCM connector A (49P).
  1. Connect ETCS control relay 4P connector terminal No. 4 to body ground with the jumper wire.
  1. Check for continuity between ECM/PCM connector terminal A21 and body ground.
Is there continuity?
YES -
Go to Step 30 .
NO -
Repair open in the wire between the ECM/PCM (A21) and the ETCS control relay, then go to Step 25 .
  1. Open the fuse lid (A), then remove the ETCS control relay (B) from the under-dash fuse/relay box.
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM/PCM connector C (49P).
RHD model
LHD model
  1. Check for continuity between ECM/PCM connector terminal C1 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM/PCM (C1) and the ETCS control relay, then go to Step 25 .
NO -
Go to Step 23 .
  1. Check for continuity between ETCS control relay 4P connector terminal No. 2 and body ground.
Is there continuity?
YES -
Replace the under-hood fuse/relay box, then go to Step 25 .
NO -
Go to Step 30 .
  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 P1659 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. 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 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.■