Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
DTC Descriptors
DTC B0455 00 : Auxiliary Heater Coolant Sensor Circuit LowDTC B0457 00 : Auxiliary Heater Coolant Sensor Circuit Open
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Auxiliary Heater Coolant Sensor Supply Voltage Circuit | B0455 00 | B0457 00 | -- | -- |
Auxiliary Heater Coolant Sensor Ground Voltage Circuit | -- | B0457 00 | B0457 00 | -- |
Circuit/System Description
The fuel operated heater uses an auxiliary heater coolant sensor to measure the coolant temperature.
Conditions for Running the DTC
Engine is running.
Conditions for Setting the DTC
Fuel operated heater has recognized out of range condition for more than 2.5 seconds.
Action Taken When the DTC Sets
Fuel operated heater is disabled.
Conditions for Clearing the DTC
DTC must be cleared with a scan tool.
Reference Information
Schematic Reference
Connector End View Reference
Cooling System Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Start the vehicle. Observe the coolant heater sensor scan tool parameter . The scan tool parameter should display between 0.09-4.9 volts.
Component Testing
- Ignition OFF, disconnect the 14-pin coolant heater module connector from the module.
- Test the coolant heater sensor resistance.
- Compare the readings with the Temperature vs Resistance table and verify that the resistance is within 5 percent of the specification.
- If the coolant heater sensor tests normal, replace the coolant heater.
| ⇒ | If the resistance vs temperature reading is not within 5 percent, replace the coolant heater sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
