Honda HR-V: DTC U1064, Seat Heater Control Unit Lost Communication With Climate Control Unit

DTC (Front Seat Heater Control Unit)

NOTE :

• If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Refer to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks.
• The 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.

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.

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. Determine possible failure area (climate control unit power and ground, B-CAN line):

1. Select B-CAN CONTROL UNITS INFORMATION from the BODY ELECTRICAL SYSTEM SELECT menu, and then select CHECK CONNECTED CONTROL UNITS.
2. Check the DETECT/NOT AVAILABLE information of the CLIMATE CONTROL/HVAC CONTROL UNIT.

Is DETECT indicated?

YES

Go to step 7.

NO

Go to step 3.

3. Fuse check:

Check the following fuse.

Is each fuse OK?

YES

Go to step 4.

NO

Replace the fuse. If the fuse blows again, repair a short to ground in the No. C24 (7.5 A) fuse circuit.

4. Open wire check (IG2 A/C line):

1. Turn the vehicle to the OFF (LOCK) mode.
2. Disconnect the following connector.

Climate control unit connector A (32P)

3. Turn the vehicle to the ON mode.
4. Measure the voltage between test points 1 and 2.

Is there battery voltage?

YES

The IG2 A/C wire is OK. Go to step 5.

NO

Repair an open or high resistance in the wire.

5. Open wire check (GND line):

1. Turn the vehicle to the OFF (LOCK) mode.
2. Check for continuity between test points 1 and 2 individually.

Is there continuity?

YES

The GND wire is OK. Go to step 6.

NO

Repair an open or high resistance in the ground wire or poor ground (G403).

6. Open wire check (B-CAN lines):

1. Disconnect the following connector.

Front seat heater control unit 14P connector

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

Is there continuity?

YES

An open or poor connection in the B-CAN_L wire between the front seat heater control unit and the climate control unit.

NO

An open or poor connection in the B-CAN_H wire between the front seat heater control unit and the climate control unit.

7. Open wire check (B-CAN lines):

1. Turn the vehicle to the OFF (LOCK) mode.
2. Disconnect the following connectors.

Front seat heater control unit 14P connector

Climate control unit connector A (32P)

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

Is there continuity?

YES

An open or poor connection in the B-CAN_L wire between the front seat heater control unit and the climate control unit.

NO

An open or poor connection in the B-CAN_H wire between the front seat heater control unit and the climate control unit.

DTC U1280 (FRONT SEAT HEATER CONTROL UNIT) SEAT HEATER CONTROL UNIT COMMUNICATION BUS LINE ERROR (BUS-OFF)

DTC (Front Seat Heater Control Unit)

NOTE :

• If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Refer to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks.
• The 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.

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.

Is DTC U1280 indicated?

YES

Go to MICU DTC U1280 troubleshooting.

NO

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

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