B0478

Read the instructions below then start the fault diagnostic procedure.

Symptom: Poor heating of cabin Heater switched off but allowed to restart

B0478

Fault symptoms

Poor heating of cabin

Heater switched off but allowed to restart

Conditions

Heater running.

The control module checks the temperature of the combustion chamber when the heater is running. If the flame temperature sensor registers a temperature below 105°C (221°F) (resistance of flame temperature <1403 Ohm) for approximately 3 minutes when the heater is running at low power, a DTC is generated.

Diagnostic help

The temperature from the flame temperature sensor can be read using the diagnostic tool.

The heater has an extra cable and connector that is separate from the ordinary wiring on the heater. This cable and connector are not used but are connected to the control module. Therefore, check that this cable is undamaged before starting fault diagnosis.

The ordinary wiring between the heater and the 8-pin connector contains an additional light-green wire that is cut and not used.