Diagnostic Communication
In or Out Signals to the ISAT Scan Tool
Fault Symptom
No contact with the electronic control module via the ISAT scan tool.
Diagnostic Procedures
1 Checking the ISAT scan tool switch.
- Connect the ISAT scan tool.
- ISAT scan tool display should come on.
Does the display come On?
YES Continue with point 5.
NO Check fuse 23 and continue with point 2.
2 Checking +30 voltage supply at the data link connector.
- Connect the test lamp between the voltage supply pin and the data link connector and a definite grounding point.
Data link Voltage
connector supply
-M94 Pin 9
M95 9
M96 (current) 16
The test lamp should come on if there is a +30 voltage supply.
Does the test lamp come on?
YES Continue with point 3.
NO Rectify the cables between the voltage supply and fuse 23.
3 Check the ground connection at the data link connector.
- Connect the test lamp between the voltage supply and the pin to ground at the data link connector.
Data link Voltage supply Power ground
connector
-M94 Pin 9 Pin 9
M95 9 10
M96 (current) 16 5
16 4
The test lamp should come on if there is a ground connection.
Does the test lamp come on?
YES Check the ISAT scan tool.
NO Rectify the wiring between the voltage supply pin and the grounding point.
Data link Grounding point
connector
-M95 G24
M96 (current) G6 or G8
4 Check the ISAT scan tool switch with the electronic control module
- Select "MEMORY SEAT":
The ISAT scan tool should display the menu for memory seat.
Does the switch belong with the electronic control module?
YES The fault is intermittent.
NO Continue with point 5.
5 Check the ISAT switch with another system.
- Choose one of the other systems that the car is equipped with.
The ISAT scan tool should display the particular selected system.
Does the switch belong with the ejected system?
YES Continue with point 6.
NO Check the ISAT scan tool.
6 Inspect the wiring harness.
- Make a continuity test in the link between the data link connector (DTC) and the electronic control module.
Data link connector Ground H8-3
-M95 Pin 1 Pin 3
5 6
6 6
M96 Pin 8 Pin 3
1 6
M96- Pin 8 Pin 5
(current) (connector B)
- The resistance should be <1 Ohm
Is the measurement value correct?
YES ECM Check
NO Rectify the wiring harness.