Vent Valve Check
Turn ignition on. Using jumper wire, apply battery voltage to CCU wiring harness connector terminal No. 7. See Fig 1 . Using another jumper wire connected to ground, repeatedly touch terminal No. 12. If vent valve does not click, replace vacuum pump or repair open circuit. If vent valve clicks, check control unit, connector pin terminals and wiring harness connector. Repair or replace as necessary.