Circuit Description
The fog lamp relay is controlled by the body control module (BCM). Battery positive voltage is applied to the relay coil when the headlamp switch is in the headlamps or park lamps ON position. The BCM grounds the fog lamp relay control circuit in order to turn ON the fog lamp relay.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2533 Front Fog Lamps Control Circuit High.
Conditions for Running the DTC
The ignition switch is in the ON position.
Conditions for Setting the DTC
All of the following conditions must be met:
| • | The BCM has received a fog lamp ON request signal from the fog lamp switch. |
| • | The fog lamp relay control circuit is shorted to battery positive voltage for 250 milliseconds. |
Action Taken When the DTC Sets
The fog lamps are inoperative.
Conditions for Clearing the DTC
| • | The BCM receives the clear code command from the scan tool. |
| • | A current DTC will clear when the conditions for setting the DTC are no longer present. |
| • | A history DTC clears after 100 malfunction free ignition cycles. |
Diagnostic Aids
| • | The fog lamps will only illuminate under the following conditions: |
| - | The park lamps or low beam headlamps are ON. |
| - | The high beam headlamps are OFF. |
| - | The fog lamp switch is pressed. |
| - | The ignition switch is in the RUN position. |
| • | If the DTC is a history DTC, the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Listen for an audible click when the fog lamp relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
-
Determines if there is a shorted relay coil or a circuit/BCM malfunction.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Fog Lights Schematics | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Does the fog lamp relay state change with each command? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 | |
Does the test lamp turn ON and OFF with each command? | Go to Step 5 | Go to Step 4 | |
4 | Test the control circuit of the fog lamp relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
5 | 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 9 | Go to Step 7 |
6 | 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 9 | Go to Step 8 |
7 | Replace the fog lamp relay. Refer to Relay Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 9 | -- |
8 | 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 9 | -- |
9 |
Does the DTC reset? | Go to Step 2 | System OK |
