Action before changing electronic controlmodule
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Action before changing electronic control
module
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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.
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1.
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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.
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2.
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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".
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3.
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Check all grounding points. If you have already done this, do it again.
Check that the power ground and the sensor are mechanically and electrically isolated.
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4.
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Check the voltage supply to the control module.
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5.
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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.
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6.
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If the original fault remains despite this, the theft alarm control module must be
changed.
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Handling electronic control modules
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All control modules are more or less sensitive to static electricity and can, if they
are handled incorrectly, be so seriously damaged as to be rendered unserviceable. It is
therefore important that the following rules are always followed when a control module is to be
removed or changed for whatever reason.
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Avoid unplugging or removing the
control module if it is not absolutely necessary.
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Never touch the connector pins and never place the control module so that the
connector pins may come into contact with anything else.
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Before unpacking a new control module, ground the packaging to the car body
and open the packaging as short a time as possible before fitting.
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When working with control modules, it is important to regularly ground yourself.
This is especially important when you have been sitting in the car, when you have changed
position or have move around the car and especially in climatic conditions with very dry air
(e.g. in the winter in cold markets).
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Avoid wearing clothes of synthetic materials.
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Avoid shoes with insulating rubber soles.
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Always handle control modules suspected of being defective in the same way.
This significantly increases the possibility of localizing the cause of the fault.
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