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 ON (II).

2.Clear the DTC with the HDS.

3.Check for Temporary DTCs or DTCs with the HDS.

Is DTC P1659 indicated?


YES - Go to 4.


NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the under-hood fuse/relay box and the ECM.n


4.Turn the ignition switch OFF.

5.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 6.


NO - Go to 13.

6.Test the ETCS control relay in the under-hood fuse/relay box.

Is the ETCS control relay OK?


YES - Go to 7.


NO - Replace the under-hood fuse/relay box, then go to 22.


7.Remove the battery.

8.Disconnect the under-hood fuse/relay box 20P (white) connector.

9.Disconnect ECM connector C (44P).

10.Check for continuity between under-hood fuse/relay box 20P (white) connector terminal No. 6 and ECM connector terminal C1.

 

Is there continuity?


YES - Go to 11.


NO - Repair open in the wire between the ECM (C1) and the under-hood fuse/relay box, then go to 22.

11.Disconnect ECM connector A (44P).

12.Check for continuity between under-hood fuse/relay box 20P (white) connector terminal No. 17 and ECM connector terminal A20.

 

Is there continuity?


YES - Go to 27.


NO - Repair open in the wire between the ECM (A20) and the under-hood fuse/relay box, then go to 22.

13.Remove the battery.

14.Disconnect the under-hood fuse/relay box 20P (white) connector.

15.Disconnect ECM connector C (44P).

16.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 22.


NO - Go to 17.

17.Install the under-hood fuse/relay box, and replace the No. 18 DBW (THROTTLE ACTUATOR CONTROL) (15 A) fuse.

18.Connect a battery.

19.Turn the ignition switch ON (II).

20.Measure voltage between ECM connector terminal C1 and body ground.

 

Is there battery voltage?


YES - Go to 27.


NO - Replace the under-hood fuse/relay box. Also replace the No. 18 DBW (THROTTLE ACTUATOR CONTROL) (15 A) fuse, then go to 21.


21.Turn the ignition switch OFF.

22.Reconnect all connectors and the battery.

23.Turn the ignition switch ON (II).

24.Reset the ECM with the HDS.

25.Do the ECM idle learn procedure.

26.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P1659 is indicated, check for poor connections or loose terminals at the under-hood fuse/relay box and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - Troubleshooting is complete.n


27.Update the ECM if it does not have the latest software, or substitute a known-good ECM.

28.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P1659 is indicated, check for poor connections or loose terminals at the under-hood fuse/relay box and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM.n