BOSCH Cis-E III System: Description
CIS-E III system uses 2 interfacing computers. Ignition Control Unit (ICU) on Audi 90 or Knock Sensor Control Unit (KSCU) on 5000S, controls the ignition system. Fuel Injection Control Unit (FICU) controls fuel injection. CIS-E III system also has self diagnosis and trouble shooting capabilities.
Input and output signals from various sensors, switches and signalling devices are constantly monitored for faults. These faults are stored in memory. Faults can be displayed by a flashing 4-digit code sequence from an LED light located on the instrument cluster.