900 SE Hatchback L4-1985cc 2.0L DOHC Turbo EFI (1997)
Engine Control Module: Description and Operation
Description Of Operation, Control Module
The Saab Trionic principally controls
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the ignition timing (by means of the ignition discharge module)
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fuel injection (which is sequential)
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boost pressure (by means of a solenoid valve)
The Trionic engine control module has a 70-pin connector and is located at the right-hand A-pillar When the powertrain is removed, the ECM connector
and its wiring are withdrawn through the bulkhead partition.
The ECM has a 32-bit processor which can perform 2 million calculations per second.
A number of sensors supply the ECM with information. The ECM processes this information using matrices which have been stored in it after engine
operation has been optimized. Examples of such important matrices are ignition timing matrices, fuel matrices and boost pressure matrices.
The ECM is programmed for the B204L and is only to be used for this engine in the Saab 900.
The ECM may be damaged by electrostatic discharges or shorting of any of its outputs. Great care must therefore be taken whenever handling the ECM
such as in connection with fault diagnosis using a BOB, for instance.
