Chart A-5-A

PFI Chart A-5-A:

PFI Fuel Injector Circuit:

DESCRIPTION:

The fuel injectors are powered through two 7.5 AMP injector fuses. The PCM/ECM 1 C/D connector pins C12,D13, D15, D16, C11, D14, C15, and C13, injector drive circuits. The PCM/ECM grounds the injector drive circuits to turn on the fuel injector to supply fuel to the engine. PCM/ECM data parameter ED30 and ED31 injector pulse width, reflects the time in milliseconds that the PCM/ECM turns on the ground to the injectors for each injector pulse.

NOTES ON FAULT TREE:

1. The injectors will not spray unless the PCM/ECM receives distributor reference. If code E012 is current, it must be repaired.

2. Using injector override, perform an RPM drop test by cutting off the fuel to each injector on command, using the on board diagnostic system. If any cylinders do not cause an RPM drop of 100 or greater when fuel is shut off to that injector, the cause could be fuel, spark, or mechanical at this point, but the problem has been isolated to the affected cylinders. Further diagnosis is required. To perform the rpm drop test, enter diagnostics, and select injector override ES04. Depressing the warmer button with ES04 displayed will select which injector will be shut off, and depressing the cooler button will cause that injector to shut off.

3. Injector flow override ES10 will actuate each injector for 5 milliseconds. Depressing the warmer button will select an injector to be tested. Depressing the cooler button will actuate the selected injector. A selected injector can be actuated only once in a given key cycle. To actuate the injector again the engine must be started, This is to prevent the engine from being flooded or damaged.