Diagnostics Communication
Fault diagnosis, diagnostics communicationFault symptom
No contact with the DI/APC control module via ISAT scan tool.
Diagnostic procedure
1 Check ISAT scan tool contact
- Connect the ISAT scan tool.
The scan tool display should light up.
Does the display light up?
YES Continue with point 5.
NO Continue with point 2.
2 Check fuse 23
- Inspect the fuse and change it it necessary.
Continue with point 3.
3 Check the power supply (+30 circuit) in the data link connector
- Connect the test lamp to pin 9 of the data link connector and a good grounding point.
The test lamp should light up if a power supply (+30 circuit) is present.
Did the test lamp light up?
YES Continue with point 4.
NO Repair or replace the lead between pin 9 and fuse 23.
4 Check the ground connection in the data link connector.
- Connect the test lamp to pins 9 and 10 of the data link connector.
The test lamp should light if there is a ground connection.
Did the test lamp light up?
YES Check the ISAT scan tool.
NO Repair or replace the lead between pin 10 and the grounding point.
Grounding point
M89 201
M90-M91 387
M92-M93 G24
5 Check ISAT scan tool contact with the DI/APC control module
- Select "DI/APC".
The ISAT scan tool should show the menu for the DI/APC system.
Is contact with the control module established?
YES The fault is of an intermittent nature.
NO Continue with point 6.
6 Check ISAT scan tool contact with another system
- Choose another system with which the car is equipped.
The SAT scan tool should show the menu for the chosen system.
Is contact established with the chosen system?
YES Continue with point 7.
NO Check the ISAT scan tool.
7 Check the wiring harness
- Check for continuity in the connection between:
- data link connector pin 1 and DI/APC control module pin 4
- data link connector pin 3 and DI/APC control module pin 24.
The resistance should be < 1 Ohm.
Is the reading correct?
YES Proceed to "Before Control Module Replacement". Service and Repair
NO Repair or replace the wiring harness.