DTC U0122

DTC U0122  : Lost Communication With VSA Modulator-Control Unit

DTC (A/T)

1. Problem verification

   - 1. Turn the vehicle to the ON mode.

   - 2. Clear the DTC with the HDS.

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

   - 4. Turn the vehicle to the ON mode.

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

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
   U0122 Lost Communication With 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 and loose terminals between the VSA modulator-control unit and the TCM. 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, VSA indicator, and brake system indicator do not go off .

3. Open wire check (F-CAN A_H line)

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

   - 2. Disconnect the following connectors.

   VSA modulator-control unit 38P connector

   TCM 58P connector

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

   Test condition	Vehicle OFF (LOCK) mode
   	VSA modulator-control unit 38P connector: disconnected
   	TCM 58P connector: disconnected
   Test point 1	VSA modulator-control unit 38P connector No. 6 - Refer to: VSA Modulator - Control Unit Connector For Inputs And Outputs (2019 2020 2021) or VSA Modulator - Control Unit Connector For Inputs And Outputs (2016 2017 2018) .
   Test point 2	TCM 58P connector No. 34 - Refer to: A/T Control System Connector for Inputs and Outputs (2016 2017 2018), or A/T Control System Connector for Inputs and Outputs (2019), or A/T Control System Connector for Inputs and Outputs (2020 2021) .

   Is there continuity?

   YES 

   The F-CAN A_H wire is OK. Go to step 4.

   NO 

   Repair an open in the F-CAN A_H wire between the VSA modulator-control unit and the TCM.

4. Open wire check (F-CAN A_L line)

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

   Test condition	Vehicle OFF (LOCK) mode
   	VSA modulator-control unit 38P connector: disconnected
   	TCM 58P connector: disconnected
   Test point 1	VSA modulator-control unit 38P connector No. 7 - Refer to: VSA Modulator - Control Unit Connector For Inputs And Outputs (2019 2020 2021) or VSA Modulator - Control Unit Connector For Inputs And Outputs (2016 2017 2018) .
   Test point 2	TCM 58P connector No. 47 - Refer to: A/T Control System Connector for Inputs and Outputs (2016 2017 2018), or A/T Control System Connector for Inputs and Outputs (2019), or A/T Control System Connector for Inputs and Outputs (2020 2021) .

   Is there continuity?

   YES 

   The F-CAN A_L wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good VSA modulator-control unit .

   NO 

   Repair an open in the F-CAN A_L wire between the VSA modulator-control unit and the TCM.