Fuel Delivery Control
FUEL DELIVERY CONTROL CIRCUITSFuel Control Reference PCM Input (CKT 430)
From the Electronic Ignition (EI) module, the PCM uses this signal to calculate engine RPM and crankshaft position. The PCM compares pulses on this circuit to reference ground CKT 453. The PCM also uses the pulses on this circuit to initiate injector pulses. If the PCM receives no pulses on this circuit, no fuel injection pulses will occur and the engine will not run.
Crankshaft Reference Ground (CKT 453)
This is a ground circuit for the digital RPM counter inside the PCM, but the wire is connected to engine ground ONLY through the Electronic Ignition (EI) module. Although this circuit is electrically connected to the PCM, it is not connected to ground AT the PCM. The PCM compares voltage pulses on the reference input CKT 430 to any on this circuit, ignoring pulses that ground on both. If the circuit is open, or connected to ground at the PCM, it may cause poor engine performance and possibly a MIL (Service Engine Soon) with no DTC.
Camshaft Position Sensor and Cam Signal (CKT 630)
The camshaft position sensor sends a signal to the PCM which uses it as a "sync pulse" to trigger the injectors in proper sequence. The cam signal is passed through the Electronic Ignition (EI) module. It is not processed in any way.
The PCM uses the cam signal to determine the position of the # ~ piston during its power stroke. This signal allows the PCM to calculate true Sequential Fuel Injection (SFI) mode of operation. A loss of this signal will set DTC P0342.
If the cam signal is lost while the engine is running, the fuel injection system will shift to a calculated sequential fuel injection mode based on the last fuel injection pulse, and the engine will continue to run. The engine can be restarted and will run in the calculated sequential mode as long as the fault is present with a 1 in 6 chance of injector sequence being correct. Refer to DTC P0342 for further information. Testing and Inspection