The keyless entry power lock system operates in order to lock or unlock all of the doors with the actuation of a single door lock switch or from a remote hand-held radio transmitter that operates at 315 megahertz. Power is available at all times from PWR ACCY Fuse A through CKT 540 (ORN) to the following components:

Each of the door lock rocker switches has 2 normally-open contacts. When you depress the upper portion of the switch in order to unlock the doors, 1 contact closes in order to apply voltage on CKT 194 (WHT). The voltage that CKT 194 (WHT) produces is applied to the unlock coil in the power lock relay and the remote control door lock receiver. Since the other side of the relay's coils are grounded by CKT 150 (BLK) at G201 (base) and G200 (upfitter provisions), the coil energizes when this voltage is applied. Relay contacts then operate in order to apply voltage on CKT 294 (TAN) to the right and side door lock motors. At the same time, CKT 194 (WHT) input to the remote control door lock receiver causes the remote control door lock receiver to energize each of the 3 outputs. The driver door unlock output switches from ground voltage in order to apply voltage on CKT 694/294 (TAN) to the left door lock actuator motor. Also, the passenger and side door unlock output switches from ground to voltage in order to apply voltage on CKT 294 (TAN) to the right and side door lock actuator motors. Finally, the rear door unlock output switches from ground to voltage in order to apply voltage on CKT 1576 (BLK)/294 (TAN) to the rear door lock actuator motor. The parallel operation of the right side door lock actuator motors by the remote control door lock receiver and the power door lock relay reduces loading on the remote control door lock receiver since this branch circuit operates only 2 door lock actuator motors.

The unlock operation from the keyless entry hand-held transmitter differs in that the transmitter opens the left door only, the rear door only, or all the doors. When you depress the unlock push-button once on the transmitter, the remote control door lock receiver verifies the access code and energizes only the driver door unlock input. If you depress the unlock push-button twice within a short period of time, all of the unlock output energize. If you depress the rear push-button, only the rear door unlock output energizes.

Each door lock actuator motor connects to the power lock relay's lock contacts by CKT 295 (GRY). The de-energized lock contacts in the power door lock relay are normally connected to ground. When the unlock relay operates and the remote control door lock receiver's unlock outputs energize, voltage applies to the motors and current flows through the power door lock relay to ground. The direction of current flow through the motors causes the motors to unlock the doors.

If you initiate the unlock operation remotely, the remote control door lock receiver's outputs switch from voltage to ground within a short period of time. If you hold the power door lock switch in the unlock position, the outputs to the motors remain energized. Each actuator motor has an internal automatic-reset solid state circuit breaker. The circuit breaker opens upon excessive current flow for too long. The circuit breaker resets automatically after a period of time when the current flow stops. The circuit breaker may also open if you hold the switch in place too long. Mechanical restraint at the lock mechanism may also cause the circuit breaker to open.

When you depress the lower portion of the power door lock switch in order to lock the doors, the switch contacts close in order to apply voltage on CKT 195 (LT BLU). This voltage is applied to the lock coil in the power door lock relay. The lock coil energizes and its' contacts operate in order to apply voltage on CKT 295 (GRY). When the lock relay operates, the ground connection breaks but the contacts of the unlock relay remain connected to ground. Also, the unlock outputs from the remote control door lock receiver de-energize and internal contacts connect to ground. Thus, voltage and grounding apply to each power door lock actuator motor and the motors operate in the direction required in order to lock the doors. Parallel paths to ground are provided for the right and side door actuator motors.

When the lock command generates by the actuation of the lock (key symbol) function on the remote transmitter, the remote control door lock receiver generates a voltage on the Lock Signal terminal. The voltage on CKT 195 (LT BLU) energizes the lock coil in the power door lock relay and the doors are all locked as described previously for the power door lock switches.

The side door lock actuator motor does not unlock the door if the door is open. The power door lock control module provides logic in order to lock the side door after you close the side door. With the side door open, actuation of the lock function locks the front and rear doors immediately. However, the side door lock actuator moor does not operate because the contacts at the side door contact plate are open. However, the lock command is represented as a voltage on CKT 195 (LT BLU) to the power door lock control module. The power door lock control module senses that the side door is open by the grounded signal from the side door jamb switch on CKT 158 (WHT/BLK).

When the side door opens and the lock command observed, the control module enables the delayed operation of the power door locks. The module waits for the side door jamb switch to open with the closure of the side door. With the door closed, a timer sets and starts timing. After approximately 5 seconds, the power door lock control module produces another lock command. The voltage on CKT 195 (LT BLU) actuates the power door lock relay in order to operate all power door lock actuator motors to lock the doors. Since the side door is now closed, contact is made through the side door contact plate and the side door locks.

If, during the 5 seconds of delay, the unlock command generates at any power door lock switch, the power door lock control module is disabled. The module does not lock the side door when the door closes.

The data link connector for the remote control door lock receiver grounds during the re-programming of the module for a new transmitter.

Refer to Transmitter Programming