DTC : U1281-00, U128C-00, U1291-00 (2019 2020 2021)

DTC U1281-00  : Lost Communication with The MICU (Body Control Module)

DTC U128C-00  : Lost Communication with The Wiper Control Unit

DTC U1291-00  : Lost Communication with The Relay Control Module

NOTE: 

• Before you troubleshoot, review the general troubleshooting information - Go to:How to Troubleshoot the Auto High-Beam (High-Beam Support System) (2019 2020 2021) .
• The DTC may be stored due a poor ground or power source failure at the transmitting control unit.

  Inspection of the power and grounds for each control unit is required prior to proceeding with this troubleshooting.

• The body control module controls the windshield wiper operation on this vehicle.

DTC (IDAS)

1. Problem verification

   - 1. Turn the vehicle to the ON mode.

   - 2. Clear the DTCs with the HDS.

   Clear DTCs

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

   - 4. Wait for at least 6 seconds.

   - 5. Check for DTCs with the HDS.

   DTC Description	DTC
   U1281-00 Lost Communication with The MICU (Body Control Module)
   U128C-00 Lost Communication with The Wiper Control Unit
   U1291-00 Lost Communication with The Relay Control Module

   Are any DTCs indicated?

   YES 

   Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Check for loose or poor connections.

2. Open wire check (B-CAN_H, B-CAN_L lines)

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

   - 2. Disconnect the following connector.

   Multipurpose camera unit 20P connector

   - 3. Disconnect the following connector according to the detected DTC.

   DTC	Connector
   U1281-00	MICU connector M (12P)
   U128C-00	MICU connector M (12P)
   U1291-00	MICU connector M (12P)

   - 4. Check for continuity between the receiving control unit and the transmitting control unit according to the detected DTC.

   Test condition

   Vehicle OFF (LOCK) mode

   B-CAN_H line 

   DTC	Receiving Control Unit	Transmitting Control Unit
   U1281-00	Multipurpose Camera Unit 20P Connector No. 6	MICU Connector M (12P) No. 7
   U128C-00	Multipurpose camera unit 20P connector No. 6 - Refer to: Multipurpose Camera Unit Connector for Inputs and Outputs (20106 2017 2018) Multipurpose Camera Unit Connector for Inputs and Outputs (2019 2020 2021)	MICU Connector M (12P) No. 7
   U1291-00	Multipurpose Camera Unit 20P Connector No. 6	MICU Connector M (12P) No. 7

   B-CAN_L line 

   DTC	Receiving Control Unit	Transmitting Control Unit
   U1281-00	Multipurpose camera unit 20P connector No. 17 - Refer to: Multipurpose Camera Unit Connector for Inputs and Outputs (20106 2017 2018) Multipurpose Camera Unit Connector for Inputs and Outputs (2019 2020 2021)	MICU Connector M (12P) No. 1
   U128C-00	Multipurpose camera unit 20P connector No. 17 - Refer to: Multipurpose Camera Unit Connector for Inputs and Outputs (20106 2017 2018) Multipurpose Camera Unit Connector for Inputs and Outputs (2019 2020 2021)	MICU Connector M (12P) No. 1
   U1291-00	Multipurpose camera unit 20P connector No. 17 - Refer to: Multipurpose Camera Unit Connector for Inputs and Outputs (20106 2017 2018) Multipurpose Camera Unit Connector for Inputs and Outputs (2019 2020 2021)	MICU Connector M (12P) No. 1

   Is there continuity?

   YES 

   The B-CAN_H and B-CAN_L wires are OK, replace the transmitting control unit according to the detected DTC.

   DTC	Transmitting Control Unit
   U1281-00	MICU
   U128C-00	MICU
   U1291-00	MICU

   NO 

   Repair an open in the wires between the receiving control unit and the transmitting control unit.