Before Control Module Replacement

Action Before Changing Electronic Control Module:

When all controls have been carried out according to the action schedule under the appropriate diagnostic trouble code or by manual fault diagnosis and no fault has been detected, it is natural to assume that the control module is faulty.

For this reason, run carefully through the following points before definitely deciding that the theft alarm control module is the cause of the fault.
1 Check one more time that all the points in the fault diagnosis schedule for the relevant diagnostic trouble code or fault symptom have been followed.
2 Study the wiring diagram for the circuit in question and make sure that you understand it. If necessary, refer to appropriate parts of the technical description and the electrical function description in Service Manual "3:2 Wiring diagrams".
3 Check all grounding point5. If you have already done this, do it again. Check that the power ground and the sensor are mechanically and electrically isolated.
4 Check the voltage supply to the control module.
5 Experience from M93 shows that most of all control modules returned in connection with warranty repairs were not faulty.
Be restrictive when changing control modules. Unnecessary replacement of control modules constitutes a large cost to Saab Automobile and its dealers. Think through possible causes of the fault before changing the control module.
6 If the original fault remains despite this, the theft alarm control module must be changed.