Operation CHARM: Car repair manuals for everyone.

Wide Open Throttle Mode

WIDE OPEN THROTTLE MODE
This is an Open Loop mode. During wide open throttle operation, the powertrain control module (PCM) receives the following inputs.
- Battery voltage
- Crankshaft position sensor
- Engine coolant temperature sensor
- Intake manifold air temperature sensor
- Manifold absolute pressure (MAP) sensor
- Throttle position sensor (TPS)
- Camshaft position sensor signal (in the distributor)

During wide open throttle conditions, the following occurs:
- Voltage is applied to the fuel injectors through the auto shutdown (ASD) relay by the powertrain control module (PCM). The PCM will then control the injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off. The PCM ignores the oxygen sensor input signal and provides a predetermined amount of additional fuel. This is done by adjusting injector pulse width.
- The PCM adjusts ignition timing by turning the ground path to the coil on and off.

The PCM opens the ground circuit to the A/C clutch relay to disengage the A/C compressor clutch. This will be done for approximately 15 seconds (if the A/C system is operating).