U0101

DTC U0101: A/T FI Signal A/B Circuit Malfunction

(2003 AT-PZEV (SULEV) and 2004-2005 models)

NOTE:
- Information marked with an asterisk (*) applies to 2003 ULEV model.
- Information marked with an asterisk (*1) applies to the TMB line.

1. Reset the ECM with the HDS.
2. Drive the car for several miles.
3. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U0101 (P1655)* indicated?

YES - Go to step 4.

NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the 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 ECM connector B (24P).
7. Disconnect TCM connector C (17P).




8. Check for continuity between ECM connector terminal B24 (B22)(*1) and body ground.

Is there continuity?

YES - Repair short in the wire between the ECM (B24 (B22)(*1)) and the TCM (C17 (C16)(*1)).

NO - Go to step 9.




9. Check for continuity between ECM connector terminal B24 (B22)(*1) and TCM 17P connector terminal No.17 (No.16)(*1).

Is there continuity?

YES - Go to step 10.

NO - Repair open in the wire between the ECM (B24 (B22)(*1)) and the TCM (C17 (C16)(*1)).

10. Substitute a known-good TCM and recheck.
11. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U0101 (P1655)* 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 TCM if it does not have the latest software, then recheck. If the symptom/indication goes away with a known-good TCM, replace the original TCM.