• | 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 provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Coolant Heater Blower Motor Control | B0450 00 | B0452 00 | B0451 00 | B0449 00 |
Coolant Heater Blower Motor Ground | -- | B0452 00 | -- | -- |
The fuel operated heater uses a coolant heater blower motor to supply oxygen onto the combustion chamber so the air fuel mixture will ignite when the glow plug is activated.
Engine is running.
The fuel operated heater has recognized out of range condition for more than 2.5 seconds.
The fuel operated coolant heater is disabled.
• | A current DTC will clear when the conditions for setting the DTC are no longer present. |
• | A history DTC will clear after 40 malfunction-free ignition cycles. |
Air Temperature Description and Operation
Control Module References for scan tool information
Ignition ON, command the Blower Motor ON and OFF with the scan tool. Verify the blower motor turns ON and OFF as commanded.
⇒ | If greater than the specified range, replace the coolant heater. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the coolant heater. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the coolant heater. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.