Test A: The Speed Control Is Inoperative

PINPOINT TEST A: THE SPEED CONTROL IS INOPERATIVE

A1-A3:

A3-A6:

Normal Operation
The powertrain control module (PCM) sends a signal through circuit 248 (TN/OG) to the speed control switches, which passes through the clockspring. The return signal is sent to the PCM through circuit 133 (BK) and the clockspring. When the brake pedal is applied the smart junction box (SJB) sends a message to the PCM to deactivate the speed control if engaged.

The speed control deactivator switch interrupts circuit 535 (LB/RD) removing the voltage signal to the PCM when the brake pedal is applied firmly and passes the stoplamp switch trip point. This is a redundant signal to the PCM.

Possible Causes
- parking brake switch circuitry
- speed control switch
- digital transmission range (TR) sensor
- vehicle speed signal
- PCM