27 Injector #1 - 4 Control Ckt - (P0201 - P0204)

27 INJECTOR #1 CONTROL CIRCUIT - (P 0201)
27 INJECTOR #2 CONTROL CIRCUIT - (P 0202)
27 INJECTOR #3 CONTROL CIRCUIT - (P 0203)
27 INJECTOR #4 CONTROL CIRCUIT - (P 0204)





The Powertrain Control Module (PCM) energizes the injector's electromagnet to cause the valve inside the injector to open. When the valve in the injector is opened, fuel is allowed to disperse through the injector, directly into the intake manifold. The amount of time the injector is energized (injection pulse width) is dependent upon the inputs to the PCM. The longer the pulse width, the greater the fuel delivery. The Automatic Shut Down (ASD) relay supplies battery voltage to all four of the injectors; the PCM energizes the injectors by providing a ground.

ENABLING CONDITIONS
- Ignition voltage must be supplied to the PCM
- ASD relay must be energized

The PCM monitors the voltage at each of the four injectors' circuits. Grounds for the injector circuits are provided by the PCM at pins 3, 4, 24, and 25. When the PCM de-energizes an injector, electromagnetic induction causes a momentary voltage increase (voltage spike). The PCM monitors this voltage spike to determine if there is an open or short in the injector's circuit.

The Malfunction Indicator Lamp (MIL) illuminates and a DTC is stored if the PCM recognizes an open or short in the injector's circuit for a period of three seconds.

The Injector Control Circuit malfunction could possibly be caused by problems with any of the following components:

- Injector (open or short)
- Injector wiring or related connectors (open or short)
- PCM