DTC : B1C55

DTC B1C55  : Driver's Heater Thermistor Circuit Open

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 - 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.

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 90 seconds.

   - 4. Check for DTCs with the HDS.

   DTC Description	DTC
   B1C55 Driver's heater thermistor circuit open

   Is DTC B1C55 indicated?

   YES 

   Go to step 2.

   NO 

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

2. Seat heater check 1

   -1. Disconnect the following connector.

   Front seat heater control unit 14P connector

   - 2. Measure the resistance between test points 1 and 2, refer to the following table.

   Test condition	Vehicle OFF (LOCK) mode Front seat heater control unit 14P connector: disconnected
   Test point 1	Front Seat Heater Control Unit 14P Connector No. 13
   Test point 2	Front Seat Heater Control Unit 14P Connector No. 7

   Courtesy of HONDA, U.S.A., INC.

   Is resistance value within the range?

   YES 

   Replace the Front Seat Heater Control Unit - Removal and Installation (2019 2020 2021) .

   NO 

   Go to step 3.

3. Seat heater check 2

   -1. Disconnect the following connector.

   Driver's seat cushion heater connector A (6P)

   - 2. Measure the resistance between test points 1 and 2, refer to the following table.

   Test condition	Vehicle OFF (LOCK) mode Front seat heater control unit 14P connector: disconnected Driver's seat heater connector A (6P): disconnected
   Test point 1	Driver's seat heater connector A (6P) (female terminals) No. 3: (1)
   Test point 2	Driver's seat heater connector A (6P) (female terminals) No. 2: (1)

   Courtesy of HONDA, U.S.A., INC.

   Courtesy of HONDA, U.S.A., INC.

   Is resistance value within the range?

   YES 

   Go to step 4.

   NO 

   Faulty thermistor; replace the driver's Seat Cushion Heater or Seat Cushion Heater - Ventilated Seats

4. Open wire check (DR TH+ line)

   -1. Connect terminals A and B with a jumper wire.

   Terminal A	Driver's seat heater connector A (6P) (female terminals) No. 3: (1)
   Terminal B	Body ground

   Courtesy of HONDA, U.S.A., INC.

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

   Test condition	Vehicle OFF (LOCK) mode Front seat heater control unit 14P connector: disconnected Driver's seat heater connector A (6P): disconnected
   Test point 1	Front Seat Heater Control Unit 14P Connector No. 13
   Test point 2	Body ground

   Is there continuity?

   YES 

   Repair an open or high resistance in the DR TH- wire.

   NO 

   Repair an open or high resistance in the DR TH+ wire.