DTC Troubleshooting
DTC Troubleshooting: P1673 (22)
DTC P1673:
Motor Control Module (MCM) Relay Stays Activated
NOTE:
- Before you troubleshoot, record all freeze data, and any on-board snapshot, and review the general troubleshooting information Initial Inspection and Diagnostic Overview.
- If the DTC cannot be cleared, do the troubleshooting for DTC U1204.
- If DTC P1673 is stored, 12 V battery may be discharged.
1. Turn the ignition switch to ON (II).
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and wait at least 40 seconds. Turn the ignition switch to ON (II) again.
4. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P1673 indicated?
YES -
Go to step 5.
NO -
Intermittent failure, the system is OK at this time.
5. Turn the ignition switch to LOCK (0).
6. Turn the battery module switch OFF.
7. Remove the IPU cover IPU Cover Removal/Installation.
8. Remove MCM relay 1 (A).
9. Measure the voltage between IPU relay holder (MCM relay 1) 8P connector terminals No. 7 and No. 8.
When turning the ignition switch from ON (II) to LOCK (0), does the voltage change from 10 V to 0 V?
YES -
Go to step 10.
NO -
Go to step 11.
10. Test MCM relay 1.
Is the relay OK?
YES -
Repair a short to power in the wire between MCM relay 1 and the MCM (A9), then go to step 14.
NO -
Replace MCM relay 1, then go to step 14.
11. Remove the PCU lid, the PCU busplate, and the PCU cover Service and Repair.
12. Disconnect MCM connector A (31P).
13. Check for continuity between MCM connector terminal A3 and body ground.
Is there continuity?
YES -
Repair a short to ground in the wire between MCM relay 1 and the MCM (A3), then go to step 14.
NO -
Go to step 21.
14. Reconnect all connectors.
15. If removed, reinstall the PCU cover, the PCU busplate, and the PCU lid Service and Repair.
16. If removed, reinstall the IPU cover IPU Cover Removal/Installation, then turn the battery module switch ON.
17. Turn the ignition switch to ON (II).
18. Clear the DTC with the HDS.
19. Turn the ignition switch to LOCK (0), and wait at least 40 seconds. Turn the ignition switch to ON (II) again.
20. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P1673 indicated?
YES -
Check for poor connections or loose terminals at MCM relay 1 and the MCM, then go to step 1.
NO -
Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.
21. Reconnect all connectors.
22. Reinstall the PCU cover, the PCU busplate, and the PCU lid Service and Repair.
23. Reinstall the IPU cover IPU Cover Removal/Installation, then turn the battery module switch ON.
24. Update the MCM if it does not have the latest software Testing and Inspection, or substitute a known-good MCM.
25. Turn the ignition switch to ON (II), and then to LOCK (0). Wait at least 40 seconds, then turn the ignition switch to ON (II) again.
26. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P1673 indicated?
YES -
If the MCM was updated, substitute a known-good MCM, then recheck. If the MCM was substituted, go to step 1.
NO -
If the MCM was updated, troubleshooting is complete. If the MCM was substituted, replace the original MCM Service and Repair. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.