AHM/PHM / B0447 00

Read the instructions below then start the fault diagnostic procedure.

Symptom: Poor cabin heating Heater does not start.

B0447 00

Fault symptom

Poor cabin heating

Heater does not start.

On-board diagnosis

Type of diagnosis:

Continuous

Enable criteria:

Ignition ON.

Fuel pump heater active

Heater not in rest mode.

Fault criteria:

Break in the heater fuel pump circuit.

System reaction to a fault:

Heater is switched off.

Checking the wiring harness

Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.

Diagnostic help

Diagnosis regards:

Electrical fault in connecting leads or component.

Functions in the diagnostic tool related to the fault:

Activate:

Fuel Pump

(See also description of readings/activations in diagnostic tool)