Part 2

Faulty signal (Continued)

Checking for an open-circuit




- Ignition off.








- Check cable between vacuum pump connector terminal 3 and control module connector terminal 7T for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.





Continue - Verification, regulator

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Checking the regulator








- Ignition off.
- Vacuum pump disconnected.




- Temporarily connect a cable between vacuum pump terminal 3 and battery positive terminal and a cable between vacuum pump terminal 1 and battery negative terminal. The regulator should click.
- Remove temporary cables.

Did the regulator click?

Yes - Checking for contact resistance and oxidation

No - Replacing component

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Checking for contact resistance and oxidation




- Ignition off.
- Check control module connector and vacuum pump connector for resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault and loose connections according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.





Continue - Verification, regulator

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Replacing component




- Ignition off.
- Try a new vacuum pump according to Replacing vacuum pump and regulator Service and Repair.





Continue - Verification, regulator

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Checking vacuum pump function












- Ignition on.
- Control module disconnected.
Connect the single cable between control module connector terminal 1S and terminal 7T.
Connect the other cable with the double blade terminal to control module connector terminal 3S, connect one end of the cable to control module connector terminal 9S.
Connect the other cable to control module connector terminal 7S, the vacuum pump should start and the vacuum servo contract.
Remove the cable from terminal 7S when the vacuum servo is fully contracted. The vacuum pump should stop.





Is the vacuum pump operating correctly?

Yes - Checking that the vacuum system is airtight

No - Checking cable to the vacuum pump

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Checking that the vacuum system is airtight












- Ignition off.
- Control module disconnected.
- Vacuum pump connected.
- Ignition on.
- Connect the single cable between control module connector terminal 1S and terminal 7T.
Connect the other cable with the double blade terminal to control module connector terminal 3S, connect one end of the cable to control module connector terminal 9S.
Connect the other cable to control module connector terminal 7S, the vacuum pump should start and the vacuum servo contract.
Remove the cable from terminal 7S when the vacuum servo is fully contracted. The vacuum pump should stop.
If the vacuum servo has not released the throttle control at all after 30 seconds, there are no leaks in the vacuum system.




- Disconnect the cable connected to control module connector terminal 9S and the vacuum servo should release.

Is the vacuum system airtight?

Yes - Checking the brake valve

No - Checking for leaks

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Checking for leaks
- Check hoses to vacuum pump and vacuum servo for leaks.

Continue - Checking the brake valve

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Checking cable to the vacuum pump












- Ignition off.
- Control module disconnected.
- Disconnect battery leads from the battery.
- Remove battery and battery shelf.
- Disconnect vacuum pump.
- Connect battery leads to battery.
Connect an ohmmeter between vacuum pump connector terminal 2 and ground.









Resistance should be infinite.

OK - Checking power supply to vacuum pump

Not OK - Checking for a short-circuit

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Checking for a short-circuit




- Ignition off.








- Check cable between vacuum pump connector terminal 2 and control module connector terminal 7S for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.





Continue - Verification, vacuum pump

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Checking power supply to vacuum pump












- Ignition off.
- Control module connected.
- Vacuum pump disconnected.
- Ignition on.








- Connect a voltmeter between vacuum pump connector terminal 2 and ground.

The voltmeter should read approx. 0 V.

OK - Checking cable resistance

Not OK - Checking for a short-circuit

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Checking for a short-circuit




- Ignition off.








- Check cable between vacuum pump connector terminal 2 and control module connector terminal 7S for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.





Continue - Verification, vacuum pump

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