Computers and Control Systems: Description and Operation

Circuit Description
CIS-Motronic controls fuel injection, ignition with cylinder knock regulation, idle speed and fuel tank ventilation through a single electronic control unit.

Fuel delivery, idle speed, and ignition timing are controlled by the Motronic control unit based on input from these components:

- Coolant temperature sensor
- Oxygen sensor
- Air flow sensor potentiometer
- Idle and full throttle switches
- Knock sensor
- Ignition distributor hall sender

The Motronic control unit controls engine management functions through signals to the following components:

- Differential pressure regulator
- Cold start valve
- Idle stabilizer valve
- Ignition coil with power stage
- Carbon canister frequency valve

The CIS-Motronic system has a permanent fault memory for self-diagnosis.