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Vacuum pump, brake system

Vacuum pump, brake system

Symptom of fault

Brakes sluggish.

Diagnostic procedure

1. Check the DRIVE function




- Connect an ISAT scan tool.



- Ignition switch in ON position.



- Select "READ ON/OFF".



- Select "DRIVE".



- Check for the presence of an input signal by moving the selector lever from P and N to another gear position.


Is the ISAT scan tool reading correct?

yes

Continue with point 2.


no

See "Fault diagnosis, DRIVE" on .


2. Check the vacuum pump's relay



- Remove the vacuum pump relay.



- Ignition switch in ON position.



- Selector lever in position P.



- Connect the test lamp to pin 85 and battery positive (B+).



- Move the selector lever to position D.


The test lamp should now light up.

Is the test lamp on?

yes

Functionality OK. Continue fault diagnosis as described in Service Manual 5 "Brakes".


no

Check the lead between pin 85 of the relay holder and pin 52 of the control module. Repair or replace the lead if necessary. If no fault can be found, continue as described on .