Schematic Reference: Fog Lights Schematics

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

1. Turn ON the ignition, with the engine OFF.
2. Place the headlamp switch in the HEADLAMP position.
3. Place the fog lamp switch in the ON position.

Do both fog lamps illuminate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

Is only one lamp inoperative?

Go to Step 4

Go to Step 5

1. Disconnect the inoperative fog lamp.
2. Probe the front fog lamps supply voltage circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 16

Go to Step 19

With a scan tool, command the fog lamps ON.

Do the fog lamps illuminate?

Go to Step 10

Go to Step 6

1. Disconnect the fog lamps relay.
2. Probe the coil side voltage supply circuit of the fog lamp relay with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 18

Probe the fog lamp relay control circuit of the fog lamp relay with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 8

Go to Step 13

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

Do the fog lamps illuminate?

Go to Step 17

Go to Step 9

1. Leave the fused jumper wire connected.
2. Disconnect one of the fog lamps.
3. Probe the front fog lamps supply voltage circuit of the disconnected fog lamp with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 21

Go to Step 22

1. Disconnect the fog lamp switch.
2. Connect a 3-amp fused jumper wire between the front fog lamp switch signal circuit and a good ground.

Do the fog lamps illuminate?

Go to Step 11

Go to Step 12

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

Did you find and correct the condition?

Go to Step 26

Go to Step 14

Test the front 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 26

Go to Step 15

Test the fog lamp relay control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 26

Go to Step 15

Inspect for poor connections at the harness connector of 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 26

Go to Step 23

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 26

Go to Step 24

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 26

Go to Step 19

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

Did you find and correct the condition?

Go to Step 26

Go to Step 25

Repair an open, high resistance, or short to ground in the coil side voltage supply circuit of the fog lamp relay. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 26

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

Did you complete the repair?

Go to Step 26

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

Did you complete the repair?

Go to Step 26

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

Did you complete the repair?

Go to Step 26

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

Did you complete the repair?

Go to Step 26

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Replace the fog lamp switch. Refer to Fog Lamp Switch Replacement .

Did you complete the replacement?

Go to Step 26

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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 26

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Replace the fog lamp relay. Refer to Relay Replacement .

Did you complete the replacement?

Go to Step 26

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3