Output Functionality
PCM outputs are tested for functionality in addition to testing for opens and shorts. When PCM provides a voltage to an output component, it can verify that command was carried out by monitoring specific input signals for expected changes. For example, when PCM commands Idle Air Control (IAC) Motor to a specific position under certain operating conditions, it expects to see a specific (target) idle speed (RPM). If it does not, it stores a DTC. PCM outputs monitored for functionality include:
- Fuel Injectors
- Ignition Coils
- Torque Converter Clutch Solenoid
- Idle Air Control
- Purge Solenoid
- EGR Solenoid (if equipped)
- LDP Solenoid
- Radiator Fan Control
- Trans Controls