ULEV Model
DTC P1655: Problem in TCM-to-ECM Communication LinesULEV Model
NOTE: Record all freeze data and review General Troubleshooting Information before you troubleshoot.
1. Turn the ignition switch OFF.
2. Wait for 1 minute. If the radiator fan is running, wait for 1 minute after the radiator fan stops.
3. Disconnect TCM connector C (17P) and ECM connector B (24P).
4. Check for continuity between TCM connector terminal C17 and ECM connector terminal B24.
Is there continuity?
YES- Go to step 5.
NO- Repair open in the wire between TCM connector terminal C17 and ECM connector terminal B24.
5. Check for continuity between TCM connector terminal C17 and body ground, or between ECM connector terminal B24 and body ground.
Is there continuity?
YES- Repair short to ground in the wire between TCM connector terminal C17 and ECM connector terminal B24.
NO- Go to step 6.
6. Connect TCM connector C (17P).
7. Turn the ignition switch ON (II).
8. Measure the voltage between ECM connector terminal B24 and body ground.
Is there about 10 V?
YES- Go to step 9.
NO- Check for loose terminal fit in the TCM connectors. If the connection is OK, 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.
9. Turn the ignition switch OFF.
10. Connect ECM connector B (24P).
11. Turn the ignition switch ON (II).
12. Measure the voltage between ECM connector terminal B24 and body ground.
Is there about 10 V?
YES- Go to step 13.
NO- 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.
13. Turn the ignition switch OFF.
14. Wait for 1 minute. If the radiator fan is running, wait for 1 minute after the radiator fan stops.
15. Disconnect TCM connector C (17P) and ECM connector B (24P).
16. Check for continuity between TCM connector terminal C16 and ECM connector terminal B22.
Is there continuity?
YES- Go to step 17.
NO- Repair open in the wire between TCM connector terminal C16 and ECM connector terminal B22.
17. Check for continuity between TCM connector terminal C6 and body ground, or between ECM connector terminal B22 and body ground.
Is there continuity?
YES- Repair short to ground in the wire between TCM connector terminal C16 and ECM connector terminal B22.
NO- Go to step 18.
18. Connect ECM connector B (24P).
19. Turn the ignition switch ON (II).
20. Measure the voltage between TCM connector terminal C16 and body ground.
Is there about 10 V?
YES- 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.
NO- Check for loose terminal fit in the ECM connectors. If the connection is OK, 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.