Part 1
Faulty signal
Checking the vacuum system
Connection
Connection of Volvo Scan Tool (ST)
Volvo ST must be connected to both VIDA PC and vehicle to DLC in passenger compartment (models 1996-) or DLC B (models -1995).
Is Volvo ST connected and switched ON?
Yes - FAULT FOUND
No - No Fault Found
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FAULT FOUND - Checking vacuum supply pipe
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Checking vacuum supply pipe
Check the vacuum supply pipe in the area of the left front headlight.
Is the vacuum supply pipe OK?
Yes - Checking ground lead and power supply
No - Repair of component
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Repair of component
Repair vacuum supply pipe in the area of the left front headlight according to Repair of vacuum pipe Service and Repair.
Continue - FAULT FOUND
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Checking ground lead and power supply
- Ignition on.
- Try to establish communication with the cruise control control module.
Was communication established with the cruise control control module?
Yes - Checking regulator function
No - No Fault Found
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Checking regulator function
- Ignition off.
- Remove central electrical unit cover.
- Disconnect control module.
- 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 the control module connector terminal 9S.
The regulator should click.
Did the regulator click?
Yes - Checking vacuum pump function
No - Checking cable to the regulator
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Checking cable to the regulator
- 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 1 and ground.
Resistance should be infinite.
OK - Checking power supply to regulator
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 1 and control module connector terminal 9S for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Continue - Verification, regulator
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Checking power supply to regulator
- Ignition off.
- Control module connected.
- Vacuum pump disconnected.
- Ignition on.
Connect a voltmeter between vacuum pump connector terminal 1 and ground.
The voltmeter should read approx. 10 V.
OK - Checking cable to the vacuum pump
Not OK - Checking for an open-circuit
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Checking for an open-circuit
- Ignition off.
- Check cable between vacuum pump connector terminal 1 and control module connector terminal 9S 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 cable to the vacuum pump
- Ignition off.
- Disconnect control module.
- Vacuum pump disconnected.
Connect an ohmmeter between vacuum pump connector terminal 3 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 3 and control module connector terminal 7T for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Continue - Verification, regulator
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Checking power supply to vacuum pump
- Ignition off.
- Connect control module.
- Vacuum pump disconnected.
- Ignition on.
Connect a voltmeter between vacuum pump connector terminal 3 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 3 and control module connector terminal 7T for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Continue - Verification, regulator
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Checking cable resistance
- Ignition off.
- Disconnect control module.
- Vacuum pump disconnected.
Connect an ohmmeter between vacuum pump connector terminal 3 and control module connector terminal 7T.
The ohmmeter should read approx. 0 ohms.
OK - Checking the regulator
Not OK - Checking for an open-circuit
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