Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC B1C56
DTC B1C56 : Driver's Heater Thermistor Circuit Short
NOTE:
- If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .
- The front seat heater control unit does not turn on the front seat heater until the seat core temperature is 185°F (85°C) or less. Make sure the seat core temperature is below 185°F (85°C) before troubleshooting.
| DTC Description | DTC |
|---|---|
| B1C56 Driver's Heater Thermistor Circuit Short |
DTC (Front Seat Heater Control Unit)
- Problem verification
-1. Clear the DTCs with the HDS.
-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 B1C56 Driver's Heater Thermistor Circuit Short Is DTC B1C56 indicated?
YES
Go to step 2.
NO
Intermittent failure, the system is OK at this time. Check for loose or poor connections.
- DTC check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Driver's seat cushion heater 4P connector -3. Turn the vehicle to the ON mode.
-4. Clear the DTCs with the HDS.
-5. Check for DTCs with the HDS.
DTC Description DTC B1C56 Driver's Heater Thermistor Circuit Short Is DTC B1C56 indicated?
YES: without power seat
Repair a short in the +THERMISTER(DR) wire.
YES: with power seat
Repair a short in the DR TH+ wire.
NO
Faulty driver's seat heater thermistor; replace the driver's seat cushion heater .
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.