Computers and Control Systems: Description and Operation

The CIS-E III (Bosch KE3-Jetronic) fuel injection system is mechanically and electronically controlled. It uses the basic CIS (K-Jetronic) system for injection, and the electronically controlled correction functions of CIS-E. The CIS-E III system differs in that it incorporates ignition management to more precisely control engine output.
The mechanical portion of the CIS-E III system consists of a mixture control unit (air flow meter and fuel distributor), control pressure regulator, auxiliary air valve, cold start valve, throttle body, injector nozzles, fuel pump and fuel filter.
The electronic portion of the system consists of an airflow sensor potentiometer, differential pressure regulator, thermo time switch, coolant temperature sensor, injection control unit, throttle valve switches, altitude correction sensor, idle speed control valve, and oxygen sensor.
The ignition portion consists of an ignition control unit, knock sensor, distributor with Hall generator, and a special ignition coil with transistorized igniter.
The CIS-E III system is designed to provide adequate operation (in a 'default' mode) in the event of a malfunction. The system is also equipped with over-voltage protection for its more sensitive electronic components.
The ECU features self diagnosis capabilities with both temporary and permanent fault code memory. Emissions related faults are stored in the permanent memory, while non emissions related faults are erased each time the engine is started. See "Computers and Control Systems" for self diagnostic procedures.