Engine Control Module (ECM)

The Engine Control Module (ECM) receives signals from Mass Airflow (MAF) sensor, Heated Oxygen Sensor (HO2S), Engine Coolant Temperature (ECT) sensor, Throttle Position (TP) sensor, Closed Throttle Position (CTP) switch, Knock Sensor (KS), Crankshaft Position (CKP) sensor, engine speed (RPM) sensor, Camshaft Position (CMP) Sensor (formally known as a Hall Effect sensor), EGR sensors and other sensors specific to the individual system. ECM uses data from these sensors to vary air/fuel mixture and ignition timing to maintain optimum performance, fuel economy and emission standards.

MFI Engine Control Module (MFI ECM) is new. A 16-bit micro-processor is used which processes up to twice as much information as the previous 8-bit version. System memory capacity has been increased from 48 K-byte to 60 K-byte.

The MFI ECM module has the same 4 connectors (64 pin total) as other MFI systems. Since terminal functions are different, DO NOT install this ECM in earlier MFI systems. See Fig 1.

NOTE: Components are grouped into 2 categories: input (sensor) devices and output (actuator) signals. INPUT DEVICES are components that control or produce voltage signals monitored by ECM. OUTPUT SIGNALS are components controlled by MFI ECM.

Fig 1: Identifying MFI System Components

Courtesy of AUDI OF AMERICA, INC.