Test Description

WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

The number(s) below refer to the step number(s) on the diagnostic table.

2: Listen for an audible click when the rear door unlock relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3: Tests for voltage at the coil side of the rear door unlock relay. The LOCKS fuse supplies power to the coil side of the rear door unlock relay.
4: Verifies that the body control module is providing ground to the rear door unlock relay.
5: Tests if ground is constantly being applied to the rear door unlock relay.

DTC B3809

Step	Action	Yes	No
Schematic Reference: Door Lock/Indicator Schematics Connector End View Reference: Power Door Systems Connector End Views or Body Control System Connector End Views in Body Control System
1	Did you perform the Door Systems Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Door Systems
2	Install a scan tool. With a scan tool, command the rear door unlock relay ON and OFF. Does the rear door unlock relay turn ON and OFF with each command?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Remove the rear door unlock relay. Probe the battery positive voltage circuit of the rear door unlock relay with a test lamp that is connected to a good ground. Does the test lamp illuminate?	Go to Step 4	Go to Step 8
4	Connect a test lamp between the door unlock relay control circuit and the battery positive voltage circuit of the rear door unlock relay. With a scan tool, command the rear door unlock relay ON and OFF. Does the test lamp turn ON and OFF with each command?	Go to Step 9	Go to Step 5
5	Does the test lamp remain illuminated without being commanded?	Go to Step 7	Go to Step 6
6	Test the door unlock relay control circuit of the rear door unlock relay for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 10
7	Test the door unlock relay control circuit of the rear door unlock relay for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 10
8	Test for an open or short to ground in the battery positive voltage circuit of the rear door unlock relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 14	Go to Step 11
9	Inspect for poor connections at the rear door unlock relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 12
10	Inspect for poor connections at the harness connector of the body control module. Refer to and Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 13
11	Repair the short to ground in the door lock actuator lock or unlock control circuits. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 14	-
12	Replace the rear door unlock relay. Did you complete the replacement?	Go to Step 14	-
13	IMPORTANT: Perform the set up procedure for the body control module. Replace the body control module. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement?	Go to Step 14	-
14	Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?	Go to Step 2	System OK