DTC U0104: Lost Communication With Adaptive Cruise Control System (ACC) Control Module (A/T, Without CAN gateway)

NOTE:  Before you troubleshoot, review the General Troubleshooting Information .

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
   U0104 Lost Communication With Adaptive Cruise Control System (ACC) Control Module

   Is DTC U0104 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 multipurpose camera 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. Open wire check (F-CAN A_H line)

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

   - 2. Disconnect the following connectors.

   Multipurpose camera unit 20P connector

   TCM 58P connector

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

   Test condition	Vehicle OFF (LOCK) mode
   	Multipurpose camera unit 20P connector: disconnected
   	TCM 58P connector: disconnected
   Test point 1	Multipurpose camera unit 20P connector No. 2 - Refer to: Multipurpose Camera Unit Connector for Inputs and Outputs (2015-17), or Multipurpose Camera Unit Connector for Inputs and Outputs (2018-19)
   Test point 2	TCM 58P connector No. 34

   Is there continuity?

   YES 

   The F-CAN A_H wire is OK. Go to step 3.

   NO 

   Repair an open in the F-CAN A_H wire between the multipurpose camera unit and the TCM.

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

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

   Test condition	Vehicle OFF (LOCK) mode
   	Multipurpose camera unit 20P connector: disconnected
   	TCM 58P connector: disconnected
   Test point 1	Multipurpose camera unit 20P connector No. 13 - Refer to: Multipurpose Camera Unit Connector for Inputs and Outputs (2015-17), or Multipurpose Camera Unit Connector for Inputs and Outputs (2018-19)
   Test point 2	TCM 58P connector No. 47

   Is there continuity?

   YES 

   The F-CAN A_L wire is OK. Update the multipurpose camera unit if it does not have the latest software , or substitute a known-good multipurpose camera unit , then recheck. If this DTC goes away and the multipurpose camera unit was updated, troubleshooting is complete. If this DTC goes away and the multipurpose camera unit was substituted, replace the original multipurpose camera unit .

   NO 

   Repair an open in the F-CAN A_L wire between the multipurpose camera unit and the TCM.