DTC P1020: Fuel Injector Control Circuit: Description

WARNING: This page is about a different car, the 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.

The PCM controls fuel delivery and determines fuel system operation on Bi-Fuel (KL6) vehicles. The PCM is not capable of operating the high current CNG fuel injectors. When CNG operation is commanded, the PCM grounds the AF enable circuit, which energizes the AF relay. The AF relay energizes all of the AF injector relays. The PCM injector control signals are routed through the AF injector relays to the Fuel Injector Control Module (FICM). The FICM generates duplicate control signals to operate the CNG injectors. When gasoline operation is commanded, the PCM opens the AF enable circuit, which de-energizes the AF relay, and all of the AF injector relays. The fuel injector control circuits are routed through the AF injector relays to the gasoline fuel injectors. A fused ignition voltage is supplied to all of the fuel injectors. The PCM monitors the status of each injector signal circuit. DTC P1020 will set if there is condition on any one of the fuel injector signal circuits, or AF injector relays.