B1C57

DTC Troubleshooting: B1C57

DTC B1C57:

Passenger's Heater Thermistor Circuit Open

NOTE:

- If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.
- 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. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0), and then back to ON (II).

3. Wait for at least 90 seconds.

4. Check for DTCs with the HDS.

Is DTC B1C57 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the circuit is OK at this time. Check for loose or poor connections between the seat heater control unit and the front passenger's seat heater.

5. Turn the ignition switch to LOCK (0).

6. Disconnect the seat heater control unit 14P connector.

7. Measure the resistance between seat heater control unit 14P connector terminals No. 5 and No. 11, then refer to the following table.

Is resistance value within the range?

YES -

Replace the seat heater control unit Service and Repair.

NO -

Go to step 8.

8. Disconnect front passenger's seat heater 4P connector.

9. Measure the resistance between front passenger's seat heater 4P connector terminals No. 2 and No. 3, then refer to the following table.

Is resistance value within the range?

YES -

Go to step 10.

NO -

Faulty seat heater thermistor; replace the front passenger's seat heater cushion heater.

10. Check for continuity between seat heater control unit 14P connector terminal No. 11 and front passenger's seat heater 4P connector terminal No. 2.

Is there continuity?

YES -

Repair an open or high resistance in the wire between seat heater control unit 14P connector terminal No. 5 and front passenger's seat heater 4P connector terminal No. 3.

NO -

Repair an open or high resistance in the wire between seat heater control unit 14P connector terminal No. 11 and front passenger's seat heater 4P connector terminal No. 2.