Diagnostic tool communication, check
Symptom: Communication between the diagnostic tool and the control module cannot be established.
Diagnostic tool communication, check |
Fault symptoms
Communication between the diagnostic tool and the control module cannot be established.Diagnostic procedure
1 Check the diagnostic tool connection
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Connect the diagnostic tool to the car's data link connector.
Does the diagnostic tool display go on?
yes |
Proceed to point 4.
no |
Check that fuse 13 is intact and continue with point 2.
2 Check the current (+30 circuit) supplied to the data link connector.
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Connect a test lamp to pin 16 of the data link connector and a good grounding point. The test lamp should light up if current (+30 circuit) is present.
Did the lamp light up?
yes |
Continue with step 3.
no |
Check and, if necessary, rectify the wiring between pin 16 and fuse 13. If the wiring is OK, continue fault diagnosis as described in the "+30 power supply" section of Service Manual 3:2 "Electrical system, wiring diagrams".
3 Check the ground connection in the data link connector.
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Connect a test lamp to pins 5 and 16 of the data link connector.
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- |
Connect a test lamp to pins 4 and 16 of the data link connector. In both cases the test lamp should light up if there is a connection to ground.
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Did the lamp light up?
yes |
Check the diagnostic tool.
no |
Repair or replace the wiring between pin 5 and grounding point G33S or else between pin 4 and grounding point G33P (LHD) or G34P (RHD).
4 Checking diagnostic tool contact with gearbox
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Select "AUT TRANSMISSION". The diagnostic tool should then display the menu for the gearbox, see
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Is the menu displayed?
yes |
Continue with step 7.
no |
Continue with point 5.
5 Checking the diagnostic tool contact with other systems
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Select another system in the car, ICE for instance. The diagnostic tool should display the menu for that system.
Is the menu displayed?
yes |
Continue with step 6.
no |
Check the diagnostic tool.
6 Check the wiring harness
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Check the continuity of the wiring harness between pin 7 of the data link connector and pin 23 of the transmission control module. The resistance should be <1 ohm.
Is the resistance correct?
yes |
Continue with step 7.
no |
Repair or replace the wiring harness and continue with point 7.
7 Final check
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Select "AUT TRANSMISSION". The diagnostic tool should now display the menu for the automatic transmission.
Is the menu displayed?
yes |
The remedial action taken was correct.
no |