Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Engine Warm-Up Mode

This is an open loop mode.
The PCM adjusts injector pulse width and controls injector synchronization by turning the individual ground paths to the injectors ON and OFF.

The PCM adjusts ignition timing and engine idle speed.
- The PCM adjusts the idle speed by controlling the idle air control motor.

The following inputs are received by the PCM:
- Engine coolant temperature
- Manifold Absolute Pressure (MAP)
- Intake air temperature
- Crankshaft position (engine speed)
- Camshaft position
- Knock sensor
- Throttle position
- A/C switch
- Battery voltage
- Power steering pressure switch
- Vehicle speed
- Speed control
- Both O2 sensors (2.0L manual trans only)
- All diagnostics