Sliding Door Does Not Lock After Closing

This complaint indicates a problem with the door lock relay, the door lock delay module, the sliding door jamb switch, or the door lock switches.

1. With sliding door closed, operate the door lock switch and check the sliding door and rear door for lock operation. If neither door locks, a defective door lock relay is indicated. The door lock relay is located under the right side of the instrument panel. If the rear door locks but the sliding door does not lock, check wiring connections to the contacts in the lock pillar and the front of the sliding door.
2. To check for proper operation of the sliding door jamb switch, use test probes to connect a 12-volt lamp between terminals F and G of the door lock delay module. The module is located under the instrument panel adjacent to the door lock relay. Do not open the module case, use test probes at the wire entry end of the case. The lamp should turn on when the sliding door is opened and should turn off when the sliding door is closed. Failure of the lamp to turn on indicates a defective switch or an open circuit to the switch. Failure of the lamp to turn off indicates a misadjusted switch or a short circuit to ground in the wire to the switch. If the switch is misadjusted, it can be corrected by backing it out of the lock pillar one or two turns.
3. Some door lock switches have been found to momentarily open the normally closed contacts as the switch rocker moves from the "lock" position to the "neutral" position. When this happens it can result in battery voltage being applied to the unlock input of the door delay lock module, causing the logic circuit to reset. To check for this condition, use a test lead to connect between terminal B and D of the switch. With the sliding door open, operate the switch momentarily to the "lock" position. Do not operate the switch to the "unlock" position while the test lead is connected between terminals B and D, as a short circuit from battery to ground would result. Close the sliding door which should lock after approximately five seconds. If the system works properly with the test lead connected but does not with the test lead removed, the switch should be replaced.
4. If the above tests have not uncovered the cause of the problem, check the inputs and outputs of the door lock delay module. A probe should be used at the wire entry end of the module case. Do not open the case. Terminal A should be at ground, and should be checked for continuity to the vehicle ground. No continuity indicates an open circuit in the wiring harness. There is no connection to cavity B of the case. Use a test probe to check for battery voltage at terminal C when the lock switch is in the "lock" position, and at terminal D when the lock switch is in the "unlock" positions. Absence of voltage at these inputs indicates an open circuit in the wiring harness or a defective switch. There is no connection to cavity E of the case. Proper operation at terminals F and G was checked in step 2 above, with terminal F being connected to the door jamb switch and terminal G to battery. Use test probes to connect a small lamp (two candlepower, such as trade no. 194, GM P/N 9421330,) between terminals H and A. Open the sliding door, operate the door lock switch and close the sliding door. The lamp should turn on momentarily (0.2 to 1.0 second) approximately five seconds after the sliding door closes. If the lamp does not turn on, the module should be replaced.