Operation CHARM: Car repair manuals for everyone.

Wide Open Throttle

This is an OPEN LOOP mode.

During wide open throttle operation the Powertrain Control Module (PCM) receives the following inputs:
- Battery voltage
- Camshaft position (CMP) sensor
- Engine coolant temperature (ECT) sensor
- Manifold absolute pressure (MAP) sensor
- Intake air temperature (IAT) sensor
- Crankshaft position (CKP) sensor
- Throttle position sensor (TPS)

Based on these inputs the PCM will:
- Apply voltage to the injectors. The PCM then controls injection sequence and pulse width by switching individual injector ground paths on and off. Oxygen sensor input is ignored. The PCM will supply a predetermined amount of additional fuel.
- Monitor oxygen sensor and fine tune air/fuel ratio by varying injector pulse width.
- Adjust ignition timing.
- De-energize A/C Compressor Clutch relay (if selected).