| Description and Operation In some markets an electrically powered booster heater is installed to improve the heating output of the highly efficient diesel engines. The electric booster heater is switched on by the powertrain control module (PCM) when the engine is running (signal D+ from the generator is active) and when the ambient temperature is lower than 5°C and the cylinder head temperature falls below 71°C. The cooling system is heated with three glow plugs which are actuated by the PCM when the engine is running. NOTE:Do not change the glow plugs separately to prevent of any coolant leaks. The glow plugs are located together in a separate housing in the coolant circuit. The heating output of the glow plugs is 750 W. | Item | Description | | 1 | Glow plugs | | 
