900 Turbo Convertible L4-1985cc 2.0L DOHC Turbo EFI (1994)
The engine control module is continuously supplied with +30 voltage and loses adapted values and diagnostic trouble codes stored in its memory
if this voltage disappears.
The ECM is adjusted for a voltage between 8 and 16 V during driving.
When the ignition is switched ON, the ECM is activated and pre-injection takes place provided certain conditions are met. The ECM then waits
for pulses from the crankshaft position sensor.
The main measured quantity for fuel injection comes from the manifold absolute pressure sensor.
There are substitute functions for all sensors apart from the crankshaft position sensor.
After the ignition has been switched OFF, all sensors which are supplied with 5 V remain activated for 15 minutes. During this time it is also
possible to carry out scan tool diagnostics. After 15 minutes, global adaptation of the main fuel matrix takes place and only the memory is then
activated.
Adaptation is important for performance, driveablity, fuel consumption and emissions. The ECM must therefore not be unnecessarily disconnected
or in any other way de-energized.