Test 7: ASCD Actuator/Pump Check

Check Vacuum Hose

Check vacuum hose between ASCD actuator and ASCD pump for damage. If hose is damaged, repair as necessary. If vacuum hose is okay, go to next step.

Check ASCD Cable

Check ASCD cable for proper adjustment. See ASCD CABLE under ADJUSTMENTS. If adjustment is incorrect, adjust as necessary. If adjustment is okay, go to next step.

Check ASCD Actuator

Disconnect vacuum hose from ASCD actuator. Using a hand-held vacuum pump, apply about 6.0" Hg of vacuum to ASCD actuator. ASCD cable should pull throttle drum and hold. Wait 10 seconds and ensure vacuum does not decrease more than 0.4" Hg. If ASCD actuator holds vacuum, go to next step. If ASCD actuator does not hold vacuum, replace ASCD actuator.

Check ASCD Pump

Disconnect ASCD vacuum hose from ASCD pump. Disconnect ASCD pump harness connector. Removal of ASCD pump may be necessary. Connect a vacuum gauge to ASCD pump. Using a fused jumper wire, apply 12 volts to terminal No. 1 at ASCD pump terminals (pump side). See Fig 1 . Ground appropriate terminal at ASCD pump and observe pump operation. See ASCD PUMP OPERATION table. If ASCD pump does not operate as specified, replace ASCD pump. If ASCD pump operates as specified, ASCD actuator/pump is okay at this time.

ASCD PUMP OPERATION

Function

Ground Terminal No. ⁽¹⁾

Operation

Air Valve

Release Valve

Vacuum Motor ⁽²⁾

Run

⁽¹⁾	Apply 12 volts to ASCD pump terminal No. 1.

⁽²⁾	During vacuum motor operation, a minimum of 5.1" Hg vacuum should be generated.

Fig 1: Testing ASCD Pump

Courtesy of NISSAN MOTOR CO., U.S.A.