Schematic Reference: Fog Lights Schematics

Connector End View Reference: Power and Grounding Connector End Views .

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

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 both of the fog lamps ON?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

Is only one fog lamp inoperative?

Go to Step 4

Go to Step 6

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

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

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

Check the FOG LP fuse for an open.

Is the FOG LP fuse open?

Go to Step 16

Go to Step 8

1. Disconnect the FOG LP relay.
2. Turn the ignition to the ON position.
3. Connect a test lamp between the switch side supply of the FOG LP relay and a ground.

Does the test lamp illuminate?

Go to Step 9

Go to Step 20

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 LP relay and a ground.

Does the test lamp illuminate?

Go to Step 10

Go to Step 20

1. Place the fog lamp switch in the ON position.
2. Connect a test lamp between the coil side supply of the FOG LP relay and the control circuit of the FOG LP relay.

Does the test lamp illuminate?

Go to Step 12

Go to Step 11

1. Disconnect the lamp switch assembly connector.
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 13

Connect a fused jumper between the switch side supply of the FOG LP 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

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

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 Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 15

Test for an open, high resistance, or short to battery positive voltage in the control circuit of the FOG LP relay . Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 21

Test for a short to ground in the fog lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 20

Inspect for poor connections at the harness connector of the lamp switch assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 26

Inspect for poor connections at the harness connector of the inoperative fog lamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 25

Inspect for poor connections at the harness connector of the FOG LP relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 27

Inspect for poor connections at the harness connector of the fuse block - underhood. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 28

Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 29

Repair an open or high resistance in the fog lamp supply voltage circuit of the inoperative fog lamp. Refer to Circuit Testing and Wiring Repairs .

Has the repair been made?

Go to Step 30

--

Repair a poor connection or an open in the ground circuit of the fog lamp switch. Refer to Circuit Testing and Wiring Repairs .

Has the repair been made?

Go to Step 30

--

Repair an open or high resistance in the ground circuit of the inoperative fog lamp. Refer to Circuit Testing and Wiring Repairs .

Has the repair been made?

Go to Step 30

--

Replace the inoperative fog lamp. Refer to Headlamp, Fog Lamp, Turn Signal Lamp, Side Marker Lamp Replacement - Front .

Has the repair been made?

Go to Step 30

--

Replace the lamp switch assembly. Refer to Headlamp Switch Replacement .

Has the repair been made?

Go to Step 30

--

Replace the FOG LP relay. Refer to Relay Replacement .

Has the repair been made?

Go to Step 30

--

Replace the fuse block - underhood. Refer to Underhood Electrical Center or Junction Block Replacement .

Has the repair been made?

Go to Step 30

--

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Has the repair been made?

Go to Step 30

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2