Operation CHARM: Car repair manuals for everyone.

Engine Warm Up

PCM MONITORS:

- Engine Temperature (ECT Sensor)
- Manifold Vacuum (MAP Sensor)
- Throttle Position (TPS)
- A/C Switch Status
- Battery Voltage
- Camshaft and Crankshaft Position (CMP and CKP Sensors)

PCM CONTROLS:

- Injector pulse width, (switching the ground on and off twice per engine revolution).
- Idle speed, through the IAC motor.
- Ignition timing.

NOTE: PCM will monitor the ECT sensor, and when the time delay has elapsed and the engine has reached operating temperature, the system will leave warm up mode and go into closed loop operation.