Diesel - Glow Plug: Pre-Glowing

With the key in the On position, the glow plug output stage and the indicator lamp are actuated by the ECM. The pre-heating time is calculated by the ECM in line with the coolant temperature. The glow plug output stage switches the current through the glow plugs. The glow plug indicator lamp goes out after a pre-glow period has elapsed. Component or cable failures in the pre-glow system are indicated by the glow plug lamp and stored in the ECM.