| Each of the 3 lock cylinders (front doors and trunk) is connected to a rod that goes to a vacuum actuator/switch assembly. When you unlock any 1 location with the key the linkage unlocks that door but also moves the vacuum actuator diaphragm to close a switch. The signal from the switch then "goes" to the vacuum pump (with circuit board) that is located under the rear seat cushion, RH side. The pump then runs in the appropriate direction for opening or closing all the *other* portals via the vacuum actuators.
In the situation that you describe I'd expect to find a defectove or disconnected vacuum servo at the trunk. If you stand behind the middle of the car, open the lid, lean forward until your head is touching the trunk floor, and look toward your knees, at the right of center you will see a rectangular flap. It is through this flap that you can access the vacuum servo and it's connector.
First check to see if the connector is okay. Removing and installing it may solve the problem. |