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 B0465 00 : Auxiliary Heater Flame Sensor Circuit LowDTC B0467 00 : Auxiliary Heater Flame Sensor Circuit Open
DTC B0478 00 : Flame Off for Minimum Power
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Coolant Heater Combustion Sensor Supply Voltage Circuit | B0465 00 | B0467 00 | -- | B0478 00 |
Coolant Heater Combustion Sensor Low Reference Circuit | -- | B0467 00 | B0467 00 | B0478 00 |
Circuit/System Description
The fuel operated heater uses a coolant heater combustion sensor to monitor flame 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 combustion 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 combustion 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 combustion 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.
