Control Switch

1. Push voltmeter positive probe into brown wire terminal at emissions box No. 1 white connector and connect negative probe to suitable ground.
2. Start engine and check for voltage during deceleration.
3. If voltage is not available, disconnect vacuum hose No. 1 from emissions box No. 1 and check for vacuum.
4. If there is no vacuum, check vacuum line for leaks, blockage or disconnected hose and repeat test.