Throttle Position Sensor (TPS)/Idle Switch (Spectrum)

Connect an ohmmeter between TPS terminals "B" and "C". See Fig 1 . Resistance should steadily decrease as throttle is opened.

Fig 1: Throttle Position Sensor/Idle Switch (Spectrum)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Throttle Position Sensor Terminal Identification (Tracker)

Courtesy of GENERAL MOTORS CORP.