Digital Control System - Turbo & QUATTRO: Description
Audi Digital Control (DC) system uses Continuous Injection System (CIS LAMBDA) system for fuel delivery and electronic controls for mixture adjustment, emission control and ignition timing. An indicator light on the dash will illuminate if detonation continues or a fault is detected in the circuits.
The electronic controls consist of an intake manifold pressure sensor (built into the ECU), air temperature sensor, coolant temperature sensor, Electronic Control Unit (ECU), crankshaft speed sensor, crankshaft reference sensor, Hall Effect switch, knock sensor, throttle valve switch, brake switch, engine overheat sensor and oxygen sensor.
The ECU uses the inputs to control the cold start valve, oxygen sensor heater, cold engine warm-up enrichment, Lambda control (frequency) valve, transistorized ignition coil, wastegate frequency valve, charcoal canister shut-off valve, fault warning light and ignition timing control.