DTC Troubleshooting: B1C58
DTC B1C58: Passenger'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
B1C58 Passenger's Heater Thermistor Circuit Short
 

1.
Problem verification:

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
B1C58 Passenger's Heater Thermistor Circuit Short
 

Is DTC B1C58 indicated?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for loose or poor connections.?
2.
DTC check:

DTC check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Front passenger'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
B1C58 Passenger's Heater Thermistor Circuit Short
 

Is DTC B1C58 indicated?

     
YES: without power seat
     
     
     
Repair a short in the +THERMISTER(AS) wire.?
     
YES: with power seat
     
     
     
Repair a short in the AS TH+ wire.?
     
NO
     
     
     
Faulty front passenger's seat heater thermistor; replace the front passenger's seat cushion heater.?