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Home >> Buick >> 1995 >> Riviera V6-3.8L SC VIN 1 >> Repair and Diagnosis >> Cruise Control >> Description and Operation >> Computer Control
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Computer Control

DESCRIPTION
When set, the cruise control system will maintain a desired vehicle speed under normal driving conditions. The system also allows the cruise control set speed to be increased or decreased using the accelerate and coast, features, and resume the desired speed after accelerating or coasting.

OPERATION
The Powertrain Control Module (PCM) receives inputs from the mode control switches, brake release switch, speed sensor and servo. In turn, it pulses the vent and vacuum solenoid valves in the servo, which then position the throttle to maintain the cruise set speed, or accelerate or coast.

There are two methods for brake disengagement of the cruise system.

1. Two electric switches mounted on the brake pedal bracket inform the PCM that the brake pedal is applied.
2. A vacuum release valve also mounted on the brake pedal bracket vents the servo diaphragm vacuum to atmosphere.

COMPONENTS
- Mode Control Switches
- "OFF"
- "ON"
- "R/A" (Resume/Accelerate)
- "SET"
- Servo
- Vacuum Release Valve
- Vacuum Switch
- Servo Position Sensor
- Vehicle Speed Sensor
- Brake Control Switch

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