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Fog Lamps Inoperative

WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
Fog Lamps Inoperative

Step Action Yes No
Schematic Reference: Fog Lights Schematics 
Connector End View Reference: Power and Grounding Connector End Views in Wiring Systems.
1 Did you perform the Lighting System Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - Lighting Systems 
2
  1. Turn the ignition to the ON position.
  2. Turn the headlamp switch to the PARK position.
  3. Place the fog lamp switch in the ON position.
Are the fog lamps ON?
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems Go to Step 3 
3 Is only one fog lamp inoperative? Go to Step 4  Go to Step 6 
4
  1. Disconnect the inoperative fog lamp.
  2. Using a test lamp connected to ground, probe the fog lamps supply voltage circuit of the inoperative fog lamp.
Does the test lamp illuminate?
Go to Step 5  Go to Step 22 
5 Using a test lamp, probe between the ground circuit and supply voltage circuit of the inoperative fog lamp.
Does the test lamp illuminate?
Go to Step 18  Go to Step 24 
6
  1. Place the headlamp switch in the HEAD position.
  2. Place the headlamp dimmer switch in the high beam position.
Do the high beam headlamps operate properly?
Go to Step 7  Go to Headlamps Inoperative - High Beams 
7 Check the FOG LP fuse for an open.
Is the FOG LP fuse open?
Go to Step 16  Go to Step 8 
8
  1. Disconnect the fog lamp relay.
  2. Turn the ignition to the ON position.
  3. Connect a test lamp between the switch side supply of the fog lamp relay and a ground.
Does the test lamp illuminate?
Go to Step 9  Go to Step 20 
9
  1. Turn the headlamp switch to the PARK position.
  2. Place the headlamp dimmer switch in the low beam position.
  3. Connect a test lamp between the coil side supply of the fog lamp relay and a ground.
Does the test lamp illuminate?
Go to Step 10  Go to Step 20 
10
  1. With the fog lamp switch in the ON position.
  2. Connect a test lamp between the coil side supply of the fog lamp relay and the control circuit of the fog lamp relay.
Does the test lamp illuminate?
Go to Step 12  Go to Step 11 
11
  1. Disconnect the multifunction turn signal switch connector (CZ).
  2. Connect a jumper between the fog lamp switch signal circuit of the fog lamp switch and ground circuit.
Do the fog lamps illuminate?
Go to Step 17  Go to Step 14 
12 Connect a fused jumper between the switch side supply of the fog lamp relay and the fog lamps supply voltage circuit of the fog lamp relay.
Do the fog lamps illuminate?
Go to Step 19  Go to Step 16 
13 Connect a fused jumper between the fog lamp switch signal circuit and ground.
Do the fog lamps illuminate?
Go to Step 23  Go to Step 14 
14 Test for an open high resistance short to battery positive voltage or a short to ground in the fog lamps switch signal circuit of the fog lamp switch. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 30  Go to Step 15 
15 Test for an open, high resistance, or short to battery positive voltage in the control circuit of the fog lamp relay. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 30  Go to Step 21 
16 Test for a short to ground in the fog lamp supply voltage circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 30  Go to Step 20 
17 Inspect for poor connections at the harness connector of the fog lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 30  Go to Step 26 
18 Inspect for poor connections at the harness connector of the inoperative fog lamp. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 30  Go to Step 25 
19 Inspect for poor connections at the harness connector of the fog lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 30  Go to Step 27 
20 Inspect for poor connections at the harness connector of the fuse block - underhood. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 30  Go to Step 28 
21 Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 30  Go to Step 29 
22 Repair an open or high resistance in the fog lamp supply voltage circuit of the inoperative fog lamp. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Has the repair been made?
Go to Step 30  -
23 Repair a poor connection or an open in the ground circuit of the fog lamp switch. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Has the repair been made?
Go to Step 30  -
24 Repair an open or high resistance in the ground circuit of the inoperative fog lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Has the repair been made?
Go to Step 30  -
25 Replace the inoperative fog lamp. Refer to Fog Lamp Replacement - Front .
Has the repair been made?
Go to Step 30  -
26 Replace the multifunction turn signal switch. Refer to Multifunction, Turn Signal Switch Replacement in Steering Wheel and Column.
Has the repair been made?
Go to Step 30  -
27 Replace the fog lamp relay. Refer to Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) in Wiring Systems.
Has the repair been made?
Go to Step 30  -
28 Replace the fuse block - underhood. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.
Has the repair been made?
Go to Step 30  -
29
IMPORTANT: Perform the set up procedures for the 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 System.Has the repair been made?
Go to Step 30  -
30 Operate the system in order to verify the repair.
Did you correct the condition?
System OK Go to Step 2