Control Assembly: Testing and Inspection

NOTE: The servos are reached by removing the center console and lower instrument panel tray(s). Service and Repair

- The table (reference image) gives vacuum system response to control lever setting. The engine must be running for the tests.
- No response from all servos at any control lever setting indicates that there is a problem either with vacuum supply, or with the control head.
- Check vacuum supply by removing the black hose from the rear of the control head with the engine running.
- No vacuum at the hose indicates a fault in the hose to the vacuum booster, or a faulty check valve.
- Vacuum at the hose when it is removed indicates a faulty control head.
- If only one or two servos fail to respond to lever position, remove the hose from the malfunctioning servo(s) and check for vacuum.
- No vacuum indicates a faulty control head or vacuum hose. Vacuum indicates a faulty servo.
- Replace faulty components as needed.