Fog Lamps Inoperative

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

Step	Action	Yes	No
Schematic Reference: Fog Lights Schematics Connector End View Reference: Master Electrical Component List DEFINITION: Use this chart if either the front or the rear fog lamp is inoperative.
1	Did you perform the Lighting System Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Lighting Systems
2	Turn ON the ignition, with the engine OFF. Turn ON the park lamps. Turn ON the fog lamps. Do both fog lamps illuminate?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Did only one lamp illuminate?	Go to Step 11	Go to Step 4
4	Install a scan tool. Turn ON the ignition, with the engine OFF. With the scan tool, command the inoperable fog lamp relay ON and OFF. Do the fog lamps turn ON and OFF with each command?	Go to Step 5	Go to Step 6
5	Remove and disconnect the front or the rear fog lamp switch. Install a jumper, between the fused F/TNKDR battery positive voltage supply circuit and the inoperable fog lamp switch signal circuit at the front or the rear fog lamp switch. Do the fog lamps illuminate?	Go to Step 12	Go to Step 9
6	Remove the fog lamp relay. Install a fused jumper across the switch relay connection. Do the fog lamps turn ON?	Go to Step 7	Go to Step 10
7	Reinstall the fog lamp relay. Disconnect the BCM connector C1. Install a fused jumper at the BCM connector C1 between the fog lamp relay control circuit and ground. Do the fog lamps illuminate?	Go to Step 15	Go to Step 8
8	Test for a short to battery positive voltage, open or a poor connection in the fog lamp relay control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and complete the repair?	Go to Step 17	Go to Step 13
9	Test for short to ground, open or a poor connection in the fog lamp switch signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and complete the repair?	Go to Step 17	Go to Step 16
10	Test for an short to ground in the fog lamp switched battery positive voltage supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 17	Go to Step 14
11	Repair the open or high resistance in the inoperative fog lamp power supply or ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 17	-
12	Replace the fog lamp switch. Refer to Fog Lamp Switch Replacement - Front . Did you complete the replacement?	Go to Step 17	-
13	Replace the fog lamp relay. Refer to Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) in Wiring Systems. Did you complete the replacement?	Go to Step 17	-
14	Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Did you complete the replacement?	Go to Step 17	-
15	IMPORTANT: Perform the setup procedure for the body control module (BCM). Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System. Replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.Did you complete the replacement?	Go to Step 17	-
16	Repair an open, high resistance or short to ground in the F/TNKDR fused battery positive voltage supplied circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 17	-
17	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 2