Idle Speed/Throttle Actuator - Mechanical: Testing and Inspection

Chart C-2A:

Wiring Diagram For Chart C-2A:

CIRCUIT DESCRIPTION:

The ECM uses the throttle opener control valve to hold the throttle open. This is to increase engine rpm during warm-up, and to obtain a normal operating temperature once the Coolant Temperature Sensor (CTS) senses the engine temperature is above 78°C (172°F).

TEST DESCRIPTION: The numbers below refer to circled numbers on the diagnostic chart.

1. Check that the control relay is supplying B+ to throttle opener valve.

2. This will determine if the problem is electrical or mechanical.

3. This checks the ECM for supplying a ground.