DTC : U1064

DTC U1064  : Seat Heater Control Unit Lost Communication with Climate Control Unit (Front Seat)

NOTE: 

• If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Go to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks .
• The front seat heater control unit does not turn on the seat heater until the seat core temperature is 85 degrees or less. Make sure the seat core temperature is below 85 degrees before troubleshooting.
• Refer to the DTC code shown on the display, and then inspect the connectors and terminals based on the instructions in the table below.
• The DTC may be stored due to the grounding failure or the power source failure at the transmitting control unit (the grounding inspection and the power source inspection on each control unit are required prior to this checking process.)

DTC (Front Seat Heater Control Unit)

1. Problem verification

   -1. Clear the DTCs with the HDS.

   Clear DTCs

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

   - 3. Wait for at least 6 seconds.

   - 4. Check for DTCs with the HDS.

   DTC Description	DTC
   U1064 Seat heater control unit lost communication with climate control unit (front seat)

   Is DTC U1064 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 lines, B-CAN_L lines)

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

   - 2. Disconnect the receiving control unit connector.

   Front seat heater control unit 14P connector

   - 3. Disconnect the transmitting control unit connector(s).

   Refer to the DTC shown on the display, then disconnect the connector(s) based on the instructions (see table).

   DTC	Connector
   U1064	Climate control unit connector A (32P)

   - 4. Check for continuity between the receiving control unit and the transmitting control unit on the B-CAN_H circuit and the B-CAN_L circuit.

   Test condition

   Vehicle OFF (LOCK) mode Front seat heater control unit 14P connector: disconnected Climate control unit connector A (32P): disconnected

   DTC	CIRCUIT NAME	RECEIVING CONTROL UNIT	TERMINAL	TRANSMITTING CONTROL UNIT	TERMINAL
   U1064	B-CAN_H	Front Seat Heater Control Unit 14P Connector	No. 11	Climate control unit connector A (32P) - Refer to: Climate Control Unit Connector for Inputs and Outputs (2016 2017 2018) or Climate Control Unit Connector for Inputs and Outputs (2019 2020 2021) .	No. 23
   	B-CAN_L	Front Seat Heater Control Unit 14P Connector	No. 10	Climate control unit connector A (32P) - Refer to: Climate Control Unit Connector for Inputs and Outputs (2016 2017 2018) or Climate Control Unit Connector for Inputs and Outputs (2019 2020 2021) .	No. 24

   Is there continuity?

   YES 

   The B-CAN_H wire and the B-CAN_L wire are OK.

   According to the detected DTC on the following table replace the correspond control unit.

   DTC	Operation for transmitting control unit
   U1281	Climate Control Unit - Removal and Installation

   NO 

   Repair an open in the B-CAN_H wire and/or the B-CAN_L wire.