900 SE Sedan V6-2498cc 2.5L DOHC (1995)
Engine Control Module: Description and Operation
Control Module (ECM)
The control module for the MOTRONIC 2.8.1 has 55 connecting pins and incorporates ignition and fuel injection control functions.
By means of input signals from a large number of sensors, the control module receives continuous information on engine load, temperature, engine
rpm, exhaust gas composition, knocking (if occurring), etc.
The control module merges this information with the programmed maps ("Kennfeld") in the permanent memory and utilizes the results to control
both ignition and fuel injection.
The control module is located behind the panel by the right-hand A pillar. The wiring is run through grommets in the bulkhead partition to the
engine bay. On removal of the power plant the control module connector and wiring is withdrawn through the bulkhead.
Manual/Automatic
The MOTRONIC control module has the same part number for cars with a manual gearbox as for cars with automatic transmission.
When a voltage is first applied to pin 42 of the control module, i.e. when D or R is selected on cars with automatic transmission, the control
module is automatically programmed for cars with automatic transmission.
On cars with a manual gearbox, no voltage is ever applied to pin 42 of the control module as in this case it is connected to ground.
