Power Door Locks - Lock Inoperative Unlock Operates

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Step	Action	Yes	No
Schematic Reference: Door Lock/Indicator Schematics DEFINITION: This diagnostic table should be used to diagnose a complete failure of all the lock functions.
1	Did you perform the Door Systems Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Door Systems
2	Actuate each door lock switch, one at a time, to the lock position. Did the doors lock from each switch?	Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS	Go to Step 3
3	Did the doors lock from any switch?	Go to Power Door Locks Inoperative - One Door or Switch	Go to Step 4
4	Remove the door lock relay. Connect a test lamp between the battery positive voltage circuit on the coil side of the door lock relay at the fuse block and a good ground. Does the test lamp illuminate?	Go to Step 5	Go to Step 14
5	Connect a test lamp between the battery positive voltage circuit on the switched side of the door lock relay at the fuse block and a good ground. Does the test lamp illuminate?	Go to Step 6	Go to Step 14
6	Connect a test lamp between the ground circuit on the coil side of the door lock relay at the fuse block and B+. Does the test lamp illuminate?	Go to Step 7	Go to Step 15
7	Connect a test lamp between the door lock control circuit of the door lock relay at the fuse block and a good ground. Actuate a door lock switch to the lock position. Does the test lamp illuminate?	Go to Step 8	Go to Step 17
8	Inspect for poor connections at the door lock relay. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS . Did you find and correct the condition?	Go to Step 18	Go to Step 9
9	Remove the door unlock relay. Connect a test lamp between the ground circuit of the door unlock relay at the fuse block and B+. Does the test lamp illuminate?	Go to Step 10	Go to Step 16
10	Install the door lock relay. Connect a fused jumper between the switched side ground circuit and the load side of the door unlock relay at the fuse block. Actuate a door lock switch to the lock position. Did the doors lock?	Go to Step 11	Go to Step 12
11	Inspect for poor connections at the door unlock relay. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS . Did you find and correct the condition?	Go to Step 18	Go to Step 13
12	Replace the door lock relay. Did you complete the repair?	Go to Step 18	-
13	Replace the door unlock relay. Did you complete the repair?	Go to Step 18	-
14	Repair the open in the door lock relay battery positive voltage circuit. Refer to CIRCUIT TESTING and WIRING REPAIRS . Did you complete the repair?	Go to Step 18	-
15	Repair the open in the door lock relay ground circuit. Refer to CIRCUIT TESTING and WIRING REPAIRS . Did you complete the repair?	Go to Step 18	-
16	Repair the open in the door unlock relay ground circuit. Refer to CIRCUIT TESTING and WIRING REPAIRS . Did you complete the repair?	Go to Step 18	-
17	Repair the open in the door lock control circuit. Refer to CIRCUIT TESTING and WIRING REPAIRS . Did you complete the repair?	Go to Step 18	-
18	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 2