Diagnostics communication
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Diagnostics communication
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Basic requirement
ISAT scan tool communication with the Motronic works satisfactorily in another
car.
Fault symptoms
No contact with the Motronic control module via the ISAT scan tool.
Diagnostic help
Check the data link connector
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A condition for communication is
that the ignition switch is in the ON position.
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Communication failure could arise as a result of dislodged pins in the data link
connector.
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Check visually that the data link connector's electrical connection is
correct.
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Diagnostic procedure
1. Check the data link connector's ground connection and power
supply
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Take voltage readings in the data
link connector between:
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Are all readings OK?
Continue with point 2.
Repair or replace the lead in question and proceed to point
3.
2. Check the communications lead
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Take resistance readings in the
data link connector across:
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Are the readings OK?
Continue with point 3.
Check the relevant lead and repair or replace it if necessary. Continue with
point 3.
3. Final check
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Connect the ISAT Scan
Tool.
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Turn the ignition switch to the ON position.
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Contact the Motronic 4.1 system.
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The ISAT scan tool should show the Motronic 4.1 menu.
Is contact established?
The steps taken to rectify the fault were correct.
Continue as described in
.