Disconnect vacuum supply (small) hose from servo. Connect vacuum gauge to end of hose. Start engine. If gauge indicates at least 10 in. Hg, go to SERVO VACUUM VALVE CHECK. If gauge does not indicate at least 10 in. Hg, check for leaking or pinched hoses.
Home/GMC/Sonoma Syclone/GMC Sonoma Syclone (1991-1992)/Repair manual/Cruise Control Systems/Source Vacuum Check
Contents
Section: Cruise Control Systems- Description & Operation
- Description
- Cruise Control Module
- Cruise Control Switch
- Set/coast
- Resume/accel
- Servo Assembly
- Astro, Bravada, Safari, Sonoma, Syclone, Typhoon & "s" & "t" Series Blazer, Jimmy & Pickup
- Suburban, Van & "r" & "v" Series Blazer, Jimmy & Pickup
- Lumina Apv, Silhouette & Trans Sport
- Brake & Clutch Release Switch/valve
- Brake & Clutch Release Switch/valve Adjustment
- Astro, Safari, Sonoma, Syclone, Typhoon & "s" & "t" Series Blazer, Jimmy & Pickup
- Bravada
- Cruise Control Does Not Engage
- Drac (speed Sensor Buffer) Inoperative
- Cruise Control Does Not Disengage Using Brake Pedal
- Speed Sensor & Buffer
- Source Vacuum Check
- Servo Vacuum Valve Check
- Servo Vent Valve Check
- Brake Release Valve Test
- Wiring Diagrams
- Abbreviations
- Accessory Drive Belts
- Adjustments
- Anti-Lock/traction Control
- Application
- Automatic Trans
- Auxiliary Emission Control Systems
- Basic Trouble Shooting
- Brakes
- Charging System
- Check Lists
- Clutches Manual & Hydraulic
- Computer Relearn
- Cruise Control Systems
- Diagnostic Connector Locations
- Differentials & Drive Axles
- Door Locks & Anti-Theft Systems
- Driveline/axles
- Driveshaft & Universal Joints
- Electrical
- Electrical Component Locations
- Emission Applications
- Engine
- Engine Performance
- Fuses & Circuit Breakers
- Gauges & Instrument Panels
- General Servicing - All Makes
- Heated Glass/defoggers
- Heater
- Identification
- Manual & Power Steering
- Manual HVAC System
- Manual Trans
- MAP Guidelines
- Mechanical
- Mechanical - Hydraulic
- Metric Conversions
- Mirrors
- Pin Voltage Charts
- Procedures
- Removal & Installation
- Reset Procedures
- Rpo Codes
- Sensor Range Charts
- Specifications
- Starter
- Steering
- Steering Column
- Steering Column Switches
- Steering Gear
- Suspension Front
- Suspension Rear
- Testing & Diagnostics
- Theory & Operation
- Traction Control Disable
- Transfer Case
- Transmission
- Wheel Alignment
- Windows
- Wiper/washer Systems
- Wiring Diagrams - Engine Performance