Circuit Description
Fuel Indicator Light (FIL) informs driver what fuel engine is operating on. This vehicle utilizes a Powertrain Control Module (PCM) and an Alternative Fuels Engine Control Module (AF ECM) in order to control engine operation. AF ECM controls CNG engine operation and PCM controls gasoline engine operation. AF ECM and PCM are connected by AFO Signal circuit. AF ECM will command CNG engine operation by grounding AFO Signal circuit. PCM will turn OFF FIL whenever AFO Signal circuit is grounded. Instrument panel gauge fuse supplies positive voltage source for FIL. PCM supplies ground path.