Procedure No. 2 (Idle Switch Circuit)

Remove cruise control ECU, but leave electrical connector(s) attached. Disconnect electrical connectors from engine control ECM and ABS/TRAC ECU. Turn ignition on.
Measure voltage between ground and following terminal of cruise control ECU connector. See Figure.
- Terminal No. 9 of 10-pin connector
With throttle valve open, voltage should be 4.5-5.5 volts. With throttle valve closed, voltage should be as follows.
- Less than one volt
If voltage is as specified, perform next procedure listed in DIAGNOSIS BY SYMPTOM table. If voltage is not as specified, disconnect electrical connector from throttle position sensor.
Connect ohmmeter between terminals No. 1 and 2 of throttle position sensor connector. See Fig 1. With throttle valve open, resistance should be infinite (no continuity). With throttle valve closed, resistance should be less than 1 ohm.
If resistance is not as specified, replace throttle position sensor. If resistance is as specified, check for faulty circuit between cruise control ECU and throttle position sensor, and between throttle position sensor and ground. If circuit is okay, replace cruise control ECU.

Fig 1: Testing Throttle Position Sensor Resistance