Speed Control

The vent and vacuum speed control solenoids are controlled by the PCM. The PCM controls them by applying or removing the ground from their respective circuits. The PCM uses input signals from various inputs to determine when these solenoids should be activated.

The vacuum solenoid maintains vacuum at a specific pressure to set, resume, or accelerate the speed control system. The vent solenoid is used to vent vacuum during deceleration, when the brakes are applied, or when the transmission is shifted into PARK or NEUTRAL.