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Control module

Control module


Saab Trionic T7 control principally:


• engine torque

• fuel injection

• ignition.


The control module for Trionic T7 has a 70-pin connector and is placed in the engine bay in front of the windscreen on the passenger side.

It has two processors. A number of sensors supply information to the control module, which processes it with the help of matrices stored in the control module after optimization of engine functions. Examples of these important matrices are the ignition timing matrices, fuel matrices and air mass matrices.

The control module can be damaged by electrostatic discharges or short-circuiting of any of its outputs. Great care must therefore be taken when handling the control module, such as when carrying out fault diagnosis with BOB.

The control module is continuously supplied with +30 and will lose adapted values and stored diagnostic trouble codes if this current disappears.

The control module is adapted for a voltage of between 8-16V when being driven.

When the ignition is switched on, the control module will be activated and the CHECK ENGINE lamp will go on continuously as a function check. The fuel pump is activated for 1 second so that fuel pressure will build up, after which the control module will await pulses from the crankshaft position sensor.

Fuel injection is controlled principally by the mass air flow sensor.

Substitute functions are available for all the sensors except the crankshaft position sensor.

An absolute pressure sensor for atmospheric pressure is integrated in the control module.

Atmospheric pressure is used to:



• Correct the PWM ratio of the charge air control valve. At low atmospheric pressure, a greater PWM ratio is required to obtain the same air mass/combustion.

• Correct the purge PWM ratio. At low atmospheric pressure, a greater PWM ratio is required to obtain the same purge flow.

• Protect the turbo from overrevving at low atmospheric pressure by limiting the max. permissible air mass per combustion.

• Block certain diagnoses at pressure lower than 72 kPa.


Once the ignition has been turned off, all the sensors supplied with 5V are activated for 15 minutes. After 15 minutes, only the memory is active. Adapted values are stored in the memory.

Adaptation is important to performance, drivability, fuel consumption and emissions. The control module must therefore not be disconnected or in any other way be de-energized unnecessarily.

Diagnostics


• If the control module program memory ROM or working memory RAM is defective, diagnostic trouble code P0605 will be generated.

• If any internal function that affects throttle control is faulty, trouble codes P1601-P1611, P1613-P1614 or P1621 will be generated.

• If the atmosphere pressure sensor is defective, diagnostic trouble codes P1631-P1633 will be generated. The starting value for charge air pressure will be used as a substitute value and purging will be blocked.