DTC U0122 (A/T System (Without CAN Gateway)) (2016 2017 2018 2019 2020)

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 (red), VSA indicator, and brake system indicator (amber) do not go off - Refer to:

   ABS indicator, brake system indicator (red), VSA indicator, and brake system indicator (amber) do not go off (Without CAN Gateway) (2016) or

   ABS indicator, brake system indicator (red), VSA indicator, and brake system indicator (amber) do not go off (With CAN Gateway (With Auto Idle Stop System)) (2016) or

   ABS indicator, brake system indicator (red), VSA indicator, and brake system indicator (amber) do not go off (With CAN Gateway (Without Auto Idle Stop System)) (2017 2018) or

   ABS indicator, brake system indicator (red), VSA indicator, and brake system indicator (amber) do not go off (Without CAN Gateway) (2017 2018) or

   ABS indicator, brake system indicator (red), VSA indicator, and brake system indicator (amber) do not go off (With CAN Gateway (With Auto Idle Stop System)) (2017 2018) .

   ABS indicator, brake system indicator (red), VSA indicator, and brake system indicator (amber) do not go off (With CAN Gateway (Without Auto Idle Stop System)) (2019 2020) or

   ABS indicator, brake system indicator (red), VSA indicator, and brake system indicator (amber) do not go off (With CAN Gateway (With Auto Idle Stop System)) (2019 2020) or

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. 38 - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (2016), or VSA Modulator-Control Unit Connector for Inputs and Outputs (2017 2018 2019 2020)
   Test point 2	TCM 58P connector No. 34

   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. 26 - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (2017 2018 2019 2020), or VSA Modulator-Control Unit Connector for Inputs and Outputs (2016)
   Test point 2	TCM 58P connector No. 47

   Is there continuity?

   YES 

   The F-CAN A_L wire is OK. Go to step 5.

   NO 

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

5. Open wire check (F-CAN B_H 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. 31 - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (2016), or VSA Modulator-Control Unit Connector for Inputs and Outputs (2017 2018 2019 2020)
   Test point 2	TCM 58P connector No. 7

   Is there continuity?

   YES 

   The F-CAN B_H wire is OK. Go to step 6.

   NO 

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

6. Open wire check (F-CAN B_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. 20 - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (2016), or VSA Modulator-Control Unit Connector for Inputs and Outputs (2017 2018 2019 2020)
   Test point 2	TCM 58P connector No. 20

   Is there continuity?

   YES 

   The F-CAN B_L wire is OK. Update the VSA modulator-control unit if it does not have the latest software , then recheck. If this DTC goes away and the VSA modulator-control unit was updated, troubleshooting is complete. If this DTC is indicated after the VSA modulator-control unit was updated, replace the VSA modulator-control unit .

   NO 

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