Fault-tracing information

Special tools: 

See 9988686

Condition 

• The fault is permanent.
• The control module is correctly connected.

Test the function of the vacuum motor and regulator. Check that the valves are able to maintain a vacuum in the vacuum servo.

The test is performed by operating the vacuum motor and regulator with extra cables connected to the control module connector.

Take care not to damage any components: Connect the cables correctly.

Carry out a visual inspection of the boots and seals at the joints.

Make two cables 

One should be a single cable with narrow blade terminals at both ends. The other is doubled at one end with a narrow tab terminal on each end.

Possible Source 

• Open-circuit in the wiring between the control module and the vacuum pump/regulator.
• Short-circuit to ground or supply in the cables between the control module and the vacuum pump/regulator.
• Defective vacuum pump/regulator.
• The vacuum pump, regulator, vacuum servo, hoses or connections are not airtight.

Fault symptom[s] 

• The cruise control does not engage.
• The cruise control does not disengage when the brake or clutch pedals are depressed.
• The vehicle speed increases constantly.