Computerized Engine Controls: Notes

Vehicles use either a Motronic 4.3 or Motronic 4.4 fuel injection and electronic ignition system. See ENGINE/VIN ID article. Vehicles with Motronic 4.3 are equipped with a EGR system, vehicles with Motronic 4.4 are not. These systems have complete self-diagnostic capabilities.

Both systems use a single Electronic Control Module (ECM) that receives input from engine monitoring sensors. These sensors include Camshaft Position (CMP) sensor, Engine Coolant Temperature (ECT) sensor, Heated Oxygen (HO2S) sensor, Knock Sensor (KS), Mass Airflow (MAF) sensor, A/C pressure sensor, EGR temperature sensor (Motronic 4.3), acceleration sensor, RPM sensor, timing pick-up, and Throttle Position (TP) sensor. ECM uses these input signals to control air/fuel mixture for emission control, fuel economy and good driveability.