The only ignition-related parts are the glow plugs, which are used to initially preheat the combustion mixture. The glow plugs are energized after turning the ignition key to the glow position. The supply voltage is at least 11.5 V and in a few seconds the spark plugs are hardened to a temperature of more than 1000°C. The heating time depends on the current engine temperature. If the engine does not start immediately, the current circuit is broken, but is closed again if the ignition key is returned to the glow position. Spark plugs cannot be repaired and are replaced if damaged. The glow plugs are located in the cylinder head. Unscrew the nuts from the spark plugs and remove the remaining parts. Remove the glow plug connectors and unscrew the glow plugs with the socket and extension. When installing, tighten the glow plugs to a torque of 13 Nm.