B0478

Read the instructions below then start the fault diagnostic procedure.

Symptom: Poor heating of cabin Heater is stopped but is permitted to restart

B0478

Fault symptoms

Poor heating of cabin

Heater is stopped but is permitted to restart

Conditions

Heater is activated.

The control module controls the combustion chamber temperature when the heater is operating and if the flame temperature sensor registers that the temperature is below 105°C (221°F) (flame temperature sensor resistance <1403 ohms) for approximately 3 minutes when the heater is set at low power, a diagnostic trouble code will be generated.

Diagnostic help

The temperature value from the flame temperature sensor can be checked using the diagnostics tool.

The heater is provided with extra cabling and connector which is isolated from the ordinary cabling from the heater. This cabling and connector is not used but is connected to the control module, therefore always check that this cabling is undamaged before beginning fault tracing.

In the ordinary cabling between the heater and the 8-pin connector, there is an extra light green lead that is cut and is not used.