Cruise Control Servo: Testing and Inspection

Check Operation of Actuator

CHECK OPERATION OF ACTUATOR

DIAGNOSIS:
- Sticking of air leaves of actuator, or sticking of valve and actuator diaphragm.




TROUBLE SYMPTOM:
- Cannot run at set speed ±3 km/h (±2 MPH).

1. CHECK FOR LEAKAGE AND STICKING OF ACTUATOR VALVE




1. Measure resistance of actuator.

Terminals / Specified resistance:
No.2 - No.1 / 55 Ohm (Vent valve)
No.2 - No.3 / 22 Ohm (Vacuum valve)
No.2 - No.4 / 55 Ohm (Safety valve)




2. Check operation of actuator.
1. Connect (+) battery cable to terminal 2 and (-) battery cable to terminal 1, 3 and 4.
2. Make sure cable moves smoothly when a vac pressure of 40.0 kPa (300 mmHg, 11.81 inHg) is applied to actuator using vacuum pump.

Stroke: 35 mm (1.38 in)
Movement time: Within 3 seconds

3. When the battery is removed from condition (2) above, make sure the cable returns to its original position smoothly.

Movement time: Within 1.5 seconds




4. Connect battery to each terminal and check cable movement when vacuum pressure is applied by vacuum pump.