Speed Control Solenoid Circuits

NAME OF CODE
Speed Control Solenoid Circuits

WHEN MONITORED
With the ignition key on, the SET button pressed, and the Powertrain Control Module (PCM) sees voltage at cavity 23.

SET CONDITION
When the PCM actuates the vacuum and vent solenoids but they do not respond.

THEORY OF OPERATION
When the "Set" switch is pressed, the vehicle must be moving forward at a speed between 35-85 MPH, with the transmission gear selector in other than park or neutral. The PCM locks in a set speed. Then the PCM energizes the vacuum solenoid to open the throttle and actuates the vent solenoid to close the throttle. These actuations are dependent on power supplied to the servo from the speed control relay through the brake switch. The system is deactivated by pressing the brake, turning the on/off switch off, or vehicle speed falling below the minimum. Reactivation can be done by repeating the previous steps or pressing resume with the vehicle speed between 35-85 MPH.

POSSIBLE CAUSES
- Solenoid control circuit open or shorted
- Vacuum or vent solenoid shorted or open
- Open power circuit to solenoids
- PCM failure