DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P1659

DTC P1659 : ETCS Control Relay OFF Malfunction

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information How to Troubleshoot the Fuel And Emissions Systems.

1. Problem verification:

-1. Turn the ignition switch to ON (II).

-2. Clear the DTC with the HDS. How to Troubleshoot the Fuel And Emissions Systems

-3. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P1659 indicated?
-YES- The failure is duplicated. Go to step 2.
-NO- Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ETCS control relay and the PCM.

2. Determine possible failure area (VBETCS line or +B ETCS line, others):

-1. Turn the ignition switch to LOCK (0).

-2. Check the following fuse.





Is the fuse OK?
-YES- Go to step 3.
-NO- Go to step 9.

3. ETCS control relay test:

-1. Remove the ETCS control relay (A) from the under-dash fuse/relay box.






-2. Test the ETCS control relay. Testing and Inspection

Is the ETCS control relay OK?
-YES- The ETCS control relay is OK. Go to step 4.
-NO- Replace the ETCS control relay, then do the repair verification.

4. Determine possible failure area (under-dash fuse/relay box, others):

-1. Turn the ignition switch to ON (II).

-2. Measure the voltage between test points 1 and 2.










Is there battery voltage?
-YES- Go to step 5.
-NO- Replace the under-dash fuse/relay box Under-Dash Fuse/Relay Box Removal and Installation, then do the repair verification.

5. Determine possible failure area (+B ETCS line, others):

-1. Measure the voltage between test points 1 and 2.










Is there battery voltage?
-YES- Go to step 7.
-NO- Go to step 6.

6. Open wire check (+B ETCS line):

-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.






-3. Measure the voltage between test points 1 and 2.










Is there battery voltage?
-YES- The +B ETCS wire is OK. Replace the under-dash fuse/relay box Under-Dash Fuse/Relay Box Removal and Installation, then do the repair verification.
-NO- Repair an open in the +B ETCS wire between the No. A22 (15 A) fuse and the under-dash fuse/relay box, then do the repair verification.

7. Open wire check (VBETCS/ETCS RLY OUT line):

-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.






-4. Check for continuity between test points 1 and 2.










Is there continuity?
-YES- The VBETCS/ETCS RLY OUT wire is OK. Go to step 8.
-NO- Repair an open in the VBETCS/ETCS RLY OUT wire between the PCM (C1) and the ETCS control relay, then do the repair verification.

8. Open wire check (ETCS RLY CL- line):

-1. Disconnect the following connector.






-2. Check for continuity between test points 1 and 2.










Is there continuity?
-YES- The ETCS RLY CL- wire is OK. Update the PCM PCM Update if it does not have the latest software, or substitute a known-good PCM Service and Repair, then do the repair verification.
-NO- Repair an open in the ETCS RLY CL- wire between the PCM (A48) and the ETCS control relay, then do the repair verification.

9. Shorted wire check (VBETCS/ETCS RLY OUT line):

-1. Remove the ETCS control relay (A) from the under-hood fuse/relay box.






-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.






-4. Check for continuity between test points 1 and 2.










Is there continuity?
-YES- Repair a short in the VBETCS/ETCS RLY OUT wire between the PCM (C1) and the ETCS control relay, then do the repair verification.
-NO- The VBETCS/ETCS RLY OUT wire is OK. Go to step 10.

10. Determine possible failure area (+B ETCS line, PCM):

-1. Check for continuity between test points 1 and 2.










Is there continuity?
-YES- Go to step 11.
-NO- Update the PCM PCM Update if it does not have the latest software, or substitute a known-good PCM Service and Repair, then do the repair verification.

11. Shorted wire check (+B ETCS line):

-1. Disconnect the following connector.






-2. Check for continuity between test points 1 and 2.










Is there continuity?
-YES- Repair a short in the +B ETCS wire between the No. A22 (15 A) fuse and the under-dash fuse/relay box, then do the repair verification.
-NO- The +B ETCS wire is OK. Check the under-dash fuse relay box, and replace it Under-Dash Fuse/Relay Box Removal and Installation if needed, then do the repair verification.

Repair verification:

-1. Turn the ignition switch to LOCK (0).

-2. Reconnect all connectors.

-3. Turn the ignition switch to ON (II).

-4. Reset the PCM with the HDS How to Troubleshoot the Fuel And Emissions Systems.

-5. Do the PCM idle learn procedure PCM Idle Learn Procedure.

-6. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P1659 indicated?
-YES- Check for poor connections or loose terminals at the ETCS control relay and the PCM. If the PCM was updated, substitute a known-good PCM Service and Repair, then recheck. If the PCM was substituted, go to step 1.
-NO- Troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.