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Sensors and Switches - Computers and Control Systems > < Chart C-2A Idle Speed Control (ISC) Check|Page 2020
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relay which has two sets of contacts. Control of the relay is by the ECM which completes a ground to energize the solenoid. When energized, idle is
increased only if A/C is "ON". When de-energized throttle opening is increased regardless of A/C position.

1.

Checks for normal operation of solenoid. With key "ON" engine not running solenoid plunger should extend.

2.

Checks for normal solenoid plunger retraction if "test" terminal is grounded.

Sensors and Switches - Computers and Control Systems > < Chart C-2A Idle Speed Control (ISC) Check|Page 2020