Low Fuel Lamp/Indicator: Description and Operation

RESERVE FUEL LAMP:
When the ignition is switched on, a positive potential is applied to terminal 39 of the DME control unit via the instrument cluster. If the reserve fuel lamp goes out when the engine is started, the potential changes to ground. If the reserve fuel lamp then lights up again or does not goes out, the DME control unit stores this information if combustion faults are detected.