DTC U0122: F-CAN Malfunction (PCM-VSA Modulator-Control Unit)

NOTE:  Before you troubleshoot, review the general troubleshooting information - Refer to: HOW TO TROUBLESHOOT THE FUEL AND EMISSIONS SYSTEMS or How to Troubleshoot the CVT System(CVT) .

DTC (PGM-FI)

1. Problem verification:

   - 1. Turn the vehicle to the ON mode.

   - 2. Clear the DTC with the HDS.

   - 3. Check for Pending or Confirmed DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
   U0122 F-CAN Malfunction (PCM-VSA Modulator-Control Unit)

   Is DTC U0122 indicated?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the VSA modulator-control unit and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.

2. VSA system check:

   - 1. Check for communication to the VSA system with the HDS.

   Does the HDS communicate with the VSA system?

   YES 

   Go to step 3.

   NO 

   Go to the symptom troubleshooting for ABS indicator, brake system indicator, and VSA indicator do not go off - Refer to: VSA System Symptom Troubleshooting - ABS indicator, brake system indicator, and VSA indicator do not go off, or VSA System Symptom Troubleshooting - VSA cannot be turned OFF .

3. Open wire check (F-CAN_H line):

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Jump the SCS line with the HDS.

   SCS Short

   - 3. Disconnect the following connectors.

   PCM connector A (51P)

   VSA modulator-control unit 38P connector

   - 4. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	PCM connector A (51P): disconnected
   	VSA modulator-control unit 38P connector: disconnected
   Test point 1	VSA modulator-control unit 38P connector No. 38
   Test point 2	PCM connector A (51P) No. 2

   Is there continuity?

   YES 

   The F-CAN_H wire is OK. Go to step 4.

   NO 

   Repair an open in the F-CAN_H wire between the PCM (A2) and the VSA modulator-control unit.

4. Open wire check (F-CAN_L line):

   - 1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	PCM connector A (51P): disconnected
   	VSA modulator-control unit 38P connector: disconnected
   Test point 1	VSA modulator-control unit 38P connector No. 26
   Test point 2	PCM connector A (51P) No. 1

   Is there continuity?

   YES 

   The F-CAN_L wire is OK. Update the VSA modulator-control unit if it does not have the latest software, then recheck. If DTC U0122 is indicated after updated, replace the VSA modulator-control unit .

   NO 

   Repair an open in the F-CAN_L wire between the PCM (A1) and the VSA modulator-control unit.