P1679
DTC P1679: RSCD Signal Circuit Malfunction1. Reset the ECM with the HDS.
2. Turn the ignition switch ON (II).
3. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1679 indicated?
YES - Go to step 4.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the motor control module, TCM, and the ECM.
4. Turn the ignition switch OFF.
5. Wait for 1 minute. If the radiator fan is running, wait for 1 minute after it stops.
6. Disconnect motor control module connector A (31P).
7. Disconnect ECM connector E (31P).
8. Check for continuity' between ECM connector terminal E17 and body ground.
Is there continuity?
YES -
- Go to step 9 (CVT model).
- Repair short in the wire between the ECM (E17) and the motor control module (M/T model).
NO -
- Go to step 17 (CVT model).
- Go to step 13 (M/T model).
9. Disconnect TCM connector C (17P).
10. Check for continuity between ECM connector terminal E17 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (E17) and the TCM (C13).
NO - Go to step 11.
11. Connect TCM connector terminals C13 and C15 with a jumper wire.
12. Check for continuity between ECM connector terminal E17 and body ground.
Is there continuity?
YES - Repair short in the wire between the TCM (C15) and the motor control module.
NO - Update the TCM if it does not have the latest software, or substitute a known-good TCM, then recheck. If the symptom/indication goes away with a known-good TCM, replace the original TCM.
13. Connect motor control module connector terminal A20 to body ground with a jumper wire.
14. Check for continuity between ECM connector terminal E17 and body ground.
Is there continuity?
YES - Go to step 15.
NO - Repair open in the wire between the ECM (E17) and the motor control module.
15. Substitute a known-good motor control module and recheck.
16. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1679 indicated?
YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.
NO - Update the motor control module if it does not have the latest software, then recheck. If the symptom/indication goes away, replace the motor control module.
17. Disconnect TCM connector C (17P).
18. Connect TCM connector terminals C13 and C15 with a jumper wire.
19. Connect motor control module connector terminal A20 to body ground with a jumper wire.
20. Check for continuity between ECM connector terminal E17 and body ground.
Is there continuity?
YES - Go to step 21.
NO - Repair open in the wire between the ECM (E17) and the motor control module.
21. Remove the jumper wire from TCM connector C (17P).
22. Reconnect TCM connector C (17P).
23. Remove the jumper wire from motor control module connector A (31P).
24. Check for continuity between TCM connector terminals C13 and C15.
Is there continuity?
YES - Go to step 25.
NO - Update the TCM if it does not have the latest software, or substitute a known-good TCM, then recheck. If the symptom/indication goes away with a known-good TCM, replace the original TCM.
25. Substitute a known-good motor control module and recheck.
26. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1679 indicated?
YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.
NO - Replace the original motor control module.