Power lock system and remote keyless entry system. Power lock switch

Power lock system and remote keyless entry system

As a preliminary diagnosis for vehicles with the power lock and Remote Keyless Entry (RKE) systems (high-line version of the Central Timer Module), note the system operation while you actuate both the Lock and Unlock functions with the power lock switches and the RKE transmitter. Then, proceed as follows:

• If the driver side front door power lock motor fails to unlock following a single press of the RKE transmitter Unlock button, test the driver unlock relay. See Relays in the Diagnosis and Testing section of this group for the procedures.
• If the entire power lock system fails to function with either the power lock switches or the RKE transmitter, check the fuses in the junction block.
• If the entire power lock system fails to function with either the power lock switches or the RKE transmitter, check the fuses in the junction block.
• If the entire power lock system functions with the RKE transmitter, but not with one or both of the power lock switches, see Power Lock Switch in the Diagnosis and Testing section of this group.
• If one power lock motor fails to operate with both of the power lock switches and/or the RKE transmitter, see Power Lock Motor in the Diagnosis and Testing section of this group.

If the problem being diagnosed involves only the RKE horn chirp or panic mode features, test the horn relay and/or headlamp relay. See Relays in the Diagnosis and Testing section of this group for the procedures.

If both of these relays check OK, further diagnosis should be performed using a DRB scan tool as described in the proper Diagnostic Procedures manual.

Power lock switch

If the problem being diagnosed involves only the power lock switch illumination LEDs, check the fused ignition switch output (run) and ground circuits at the power lock switch connector. For circuit descriptions and diagrams, refer to 8W-61 - Power Door Locks in Group 8W - Wiring Diagrams.

(1) Check the fuse in the junction block. If OK, go to Step 2. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.

(2) Check for battery voltage at the fuse in the junction block. If OK, go to Step 3. If not OK, repair the open circuit to the Power Distribution Center (PDC) as required.

(3) Disconnect and isolate the battery negative cable. Unplug the wire harness connector from the power lock switch.

(4) Connect the battery negative cable. Check for battery voltage at the fused B(+) circuit cavity of the body half of the power lock switch wire harness connector.

If OK, go to Step 5. If not OK, repair the open circuit to the junction block as required.

(5) Test the power lock switch continuity. See the Power Lock Switch Continuity charts to determine if the continuity is correct in the Off, Lock and Unlock switch positions (Fig. 1) or (Fig. 2). If OK, repair the door lock switch output (lock and/or unlock) circuit(s) from the body half of the power lock switch wire harness connector to the Central Timer Module (CTM) as required. If not OK, replace the faulty switch.

Fig. 1 Power Lock Switch Continuity - Driver Side

Fig. 2 Power Lock Switch Continuity - Passenger Side