( TF09E1PK771000U0121FAAT20 )

( TF09E1PK771000U0121FAAT20 )

DTC Troubleshooting: U0121 (107) - A/T System

DTC U0121:

F-CAN Malfunction (PCM-ABS Modulator-Control Unit)

Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review General Troubleshooting Information.

Clear the DTC with the HDS.

Start the engine, and run it at idle for at least 2 minutes.

Check whether DTC U0121 is indicated in the DTCs/Freeze Data in PGM-FI Mode Menu with the HDS.

Is DTC U0121 indicated in the PGM-FI system?

YES	-	Troubleshoot DTC U0121 in the PGM-FI system. ■
NO	-	Go to Step 4 .

Check whether DTC U0121 is indicated in the DTCs/Freeze Data in A/T Mode Menu with the HDS.

Is DTC U0121 indicated?

YES	-	Go to Step 5 .
NO	-	Intermittent failure, the system is OK at this time.■

Update the A/T software in the PCM if it does not have the latest software, or substitute a known-good PCM.

Check for Temporary DTCs or DTCs with the HDS.

Is DTC U0121 indicated?

YES	-	If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to Step 1 .
NO	-	Go to Step 7 .

Monitor the OBD status for U0121 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the HDS indicate PASSED?

YES	-	If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other DTCs were indicated on Step 6 , go to the indicated DTC's troubleshooting.■
NO	-	Check for poor connections and loose terminals at the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to Step 1 . If the HDS indicates NOT COMPLETED, return to Step 7 and recheck.