Diagnostic Aids

WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

If the DTC B2742 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
An intermittent short to ground in the following locations may cause an intermittent malfunction to occur:
- The signal circuit of the fog lamp switch
- The fog lamp switch
- The BCM

DTC B2742

Step	Action	Yes	No
Schematic Reference: Fog Lights Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems.
1	Did you perform the Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Lighting Systems
2	Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, observe the front fog lamps parameter in the body control module data list. Does the scan tool display OFF?	Go to Step 3	Go to Step 4
3	Activate the fog lamps. With the scan tool, observe the front fog lamps parameter. Does the front fog lamps parameter change state?	Go to Diagnostic Aids	Go to Step 4
4	Turn OFF the ignition. Disconnect the fog lamp switch. Turn ON the ignition, with the engine OFF. With a scan tool, observe the front fog lamps parameter. Does the scan tool display OFF?	Go to Step 7	Go to Step 5
5	Test the signal circuit of the fog lamp switch for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 10	Go to Step 6
6	Inspect for a poor connection at the harness connector of the body control module (BCM). 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 10	Go to Step 8
7	Inspect for a poor connection at the harness connector of the fog lamp switch. 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 10	Go to Step 9
8	IMPORTANT: Perform the set up procedure for the body control module (BCM). Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control Systems. Replace the BCM. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement?	Go to Step 10	-
9	Replace the fog lamp switch. Refer to Fog Lamp Switch Replacement - Front . Did you complete the replacement?	Go to Step 10	-
10	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