Schematic Reference: Fog Lights Schematics

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

1. Turn ON the ignition, with the engine OFF.
2. Place the headlamp switch in the headlamp ON position.
3. Ensure headlamps are in the LOW BEAM position
4. Place the fog lamp switch in the ON position.

Do both fog lamps illuminate?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Is only one lamp inoperative?

Go to Step 4

Go to Step 6

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

Did you find and correct the condition?

Go to Step 24

Go to Step 5

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

Did you find and correct the condition?

Go to Step 24

Go to Step 16

With a scan tool, command the fog lamps ON.

Do the fog lamps illuminate?

Go to Step 10

Go to Step 7

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

Does the test lamp illuminate?

Go to Step 8

Go to Step 18

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

Does the test lamp illuminate?

Go to Step 9

Go to Step 19

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 17

Go to Step 13

1. Disconnect the fog lamp switch.
2. Momentarily connect a 3-amp fused jumper wire between the front fog lamp switch signal circuit of the switch and battery positive voltage.

Do the fog lamps illuminate?

Go to Step 11

Go to Step 12

Test the ignition 1 voltage circuit of the fog lamp switch for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 14

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

Did you find and correct the condition?

Go to Step 24

Go to Step 15

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

Did you find and correct the condition?

Go to Step 24

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 in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 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 Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 22

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 in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 20

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

Did you find and correct the condition?

Go to Step 24

Go to Step 23

Repair a short to ground in the front fog lamp supply voltage circuit of the fog lamps. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 24

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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 in Wiring Systems.

Did you complete the repair?

Go to Step 24

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Replace the bulb or lamp assembly. Refer to Front Fog Lamp Bulb Replacement or Front Fog Lamp Replacement .

Did you complete the replacement?

Go to Step 24

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

Did you complete the replacement?

Go to Step 24

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Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 24

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Replace the fog lamp relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 24

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3