Control Unit
The control unit receives signals from mass airflow sensor, oxygen sensor(s), coolant temperature sensor, throttle position sensor, closed throttle position switch, knock sensor(s), oxygen sensor(s), crankshaft position sensor, engine speed sensor, Hall Effect sensor, EGR sensors and other sensors specific to the individual system. The control unit uses data from these sensors to vary air/fuel mixture and ignition timing to maintain optimum performance, fuel economy and emission standards.
The Engine Control Module (MPI 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 MPI ECM module has same 4 connectors (64 pins total) as other MPI systems. Since terminal functions differ, this control module must NOT be installed in earlier MPI systems. See Fig 1 .