AHM/PHM / B0478 00

Read the instructions below then start the fault diagnostic procedure.

Symptom: Poor cabin heating

B0478 00

Fault symptom

Poor cabin heating

On-board diagnosis

Type of diagnosis:

Continuous

Enable criteria:

Ignition ON.

Heater is activated.

Fault criteria:

No flame in low output mode.

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:

Test value:

Flame Detected

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