Checking Speed and Idle Signal For Idle Control Unit

1. Speed signal

a. Connect LED test light between terminals 3 and ground (4). While cranking the engine, LED should flicker.
b. If LED does not flicker, check for continuity (0 Ohms) between terminal 3 and socket 13 of the diagnostic socket. Repair open circuit as necessary.


2. Idle signal

a. Connect ohmmeter between terminals 4 and 12. With ignition OFF, accelerator pedal in rest position, continuity should exist.
b. With ignition OFF, accelerator pedal in part-throttle position, continuity should not exist.
c. If switch does not operate as indicated, check throttle switch adjustment and connections.