U Code Charts

DTC U0101: A/T FI Signal A/B Malfunction - 2004 CVT model

NOTE: Information marked with an asterisk (*) applies to 2002-2003 CVT models.

1. Reset the ECM.
2. Drive the vehicle for several miles so the transmission upshifts and downshifts several times.

Is DTC U0101 (P1655)* indicated?

YES - Go to step 3.

NO - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the TCM and the ECM.

3. Turn the ignition switch OFF.
4. Disconnect ECM connector C (31).
5. Disconnect the 22P connector form the TCM.




6. Check for continuity between body ground and ECM connector terminals C15 and C11.

Is there continuity?

YES - Repair short in the wire between the ECM (C15, C11) and the TCM.

NO - Go to step 7.




7. Check for continuity between ECM connector terminal C15 and TCM 22P connector terminal No. 7, and between ECM connector terminal C11 and TCM 22P connector terminal No. 6.

Is there continuity?

YES - Check the these items:
- 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.
- Substitute a known-good TCM and recheck. If the symptom/indication goes away, replace the original TCM.

NO - Repair open in the wire between the ECM (C15, C11) and the TCM.