No Communication With The ABS

No Communication With The ABS.

Fault symptoms
No communication with the ABS.

Condition
The following conditions are applicable:
- Ignition switch in ON position

Diagnostic help
First check the fuses for the ABS control module and that no slide-out of the data link connector pins for communication with the ABS has occurred. Then check whether the ABS control module is awake and allows diagnostics communication. If this is the case, check whether the diagnostics tool works on another car.

If no fault can be found, repair or replace the communication lead between the ABS and the data link connector.

Checking the wiring harness
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short-circuits in the leads. Observe the multimeter, test lamp or diagnostic tool during the test.

Diagnostic procedure

1 Quick check
- Check that fuse 26 is intact.





- Inspect pin 8 of the data link connector visually for possible pin slide-out.





Function OK?
YES
- Go to point 2.
NO
- Rectify the fault.
- Go to point 6.

2 Checking that the ABS control module is awake
- Turn the ignition switch to ON.





- The ABS lamp should come on for 3 seconds and then go out.





Function OK?
YES
- Go to point 3.
NO
- Go to point 4.

3. Checking the diagnostic tool
- Check whether the ABS can be contacted on another Saab 9 - 5 using the same diagnostic tool.





Function OK?
YES
- Repair or replace the wiring between pin 8 of the data link connector and pin 11 of the ABS control module.
- Go to point 6.
NO
- Repair the diagnostic tool or change it, if necessary.
- Go to point 6.

4 Checking the ABS control module's current supply (+15 circuit)
- Unplug the connector: Control module, ABS: (574)





- Turn the ignition switch to ON.





- Connect test lamp 86 11 857 to pin 15 of the control module's female connector and a good ground.





- The test lamp should light.





Function OK?
YES
- Go to point 5.
NO
- Repair or replace the relevant lead.
- Go to point 6.

5. Checking the ABS control module's ground connection
- Connect test lamp 86 11 857 to pins 15 and 19 of the control module's female connector.





- The test lamp should light.





Function OK?
YES
- Go to point 6.
NO
- Repair or replace the relevant lead.
- Go to point 6.

6 Final check
- Clear the diagnostic trouble codes in all systems.





- Carry out a function test.

Function OK?
YES
- The steps taken to rectify the fault were correct.
NO
- See "Before changing a control module." Before Changing A Control Module