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.

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, with the engine OFF.
2. Turn the headlamp switch to the PARK position.
3. Turn the fog lamps to the ON position.

Do both fog lamps illuminate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

Using a scan tool, command the fog lamps on.

Do the fog lamps illuminate?

Go to Step 6

Go to Step 4

1. Disconnect the front fog relay.
2. Probe the switch side battery positive voltage circuit of the front fog relay with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 12

Go to Step 5

Connect a 10-amp fused jumper wire between the switch side battery positive voltage circuit of the front fog relay and the fog lamp voltage supply circuit of the front fog relay.

Do the fog lamps illuminate?

Go to Step 13

Go to Step 9

Using a scan tool, observe the fog lamp switch data parameter while pressing the fog lamp switch.

Does the scan tool display active when pressing the switch and inactive when you release the switch?

Go to Step 14

Go to Step 7

1. Disconnect the fog lamp switch.
2. Observe the fog lamp switch data parameter.

Does the scan tool display inactive?

Go to Step 8

Go to Step 10

1. Connect a 3-amp fused jumper wire between the fog lamp switch signal circuit of the fog lamp switch and a good ground.
2. Observe the fog lamp switch data parameter.

Does the scan tool display active?

Go to Step 15

Go to Step 11

Test for an open, high resistance, or short to ground in the fog lamp voltage supply circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 16

Test fog lamp switch signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 14

Test fog lamp switch signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 14

Inspect the front fog lamp fuse for an open.

Is the fuse open?

Go to Step 17

Go to Step 16

Inspect for poor connections at the front fog relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 18

Inspect for poor connections at 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 22

Go to Step 19

Inspect for poor connections at the fog lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 20

Inspect for poor connections at 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 22

Go to Step 21

Repair a short to ground in the back up lamp voltage supply circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 22

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Replace the fog lamp relay. Refer to Relay Replacement .

Did you complete the replacement?

Go to Step 22

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

Did you complete the replacement?

Go to Step 22

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Replace the fog lamp switch.

Did you complete the replacement?

Go to Step 22

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

Did you complete the replacement?

Go to Step 22

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2