The fog lamp relay is controlled by the body control module (BCM). On the Chevrolet, battery positive voltage is applied to the relay coil when the headlamp switch is in the PARK or HEAD position. On the Pontiac, battery positive voltage is applied to the relay coil at all times. The BCM grounds the fog lamp relay control circuit in order to turn ON the fog lamp relay. When the fog lamp relay control circuit opens or becomes shorted to ground without being commanded ON by the BCM, DTC B2532 is set.
• | The ignition switch is in the ON position. |
• | The headlamp switch is in the HEAD or PARK position. |
• | The ignition switch is in the ON position. |
• | The headlamp switch is the HEAD or PARK position. |
• | The fog lamp relay control circuit is open or shorted to ground for 5 seconds. |
• | DTC B2532 is stored in the BCM memory. |
• | If the fog lamp relay control circuit is shorted to ground, the fog lamps are always ON when the headlamps or park lamps are ON. |
• | If the fog lamp relay control circuit is open, the fog lamps are inoperative. |
• | The conditions for setting the DTC are no longer present. |
• | A history DTC clears after 100 malfunction free ignition cycles. |
• | The BCM receives the clear code command from the scan tool. |
• | The fog lamps will only illuminate under the following conditions: |
- | The park lamps or low beam headlamps are ON. |
- | The highbeam headlamps are OFF. |
- | The fog lamp switch is the ON 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. |
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.
Tests for voltage at the coil side of the fog lamp relay.
Verifies that the body control module is providing ground to the fog lamp relay.
Tests if ground is constantly being applied to the fog lamp relay.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Fog Lights Schematics | |||
1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | |
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 illuminate? | Go to Step 4 | Go to Step 10 | |
Does the test lamp turn ON and OFF with each command? | Go to Step 8 | Go to Step 5 | |
Does the test lamp remain illuminated with each command? | Go to Step 7 | Go to Step 6 | |
6 | Test the control circuit of the fog lamp relay for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
7 | Test the control circuit of the fog lamp relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
8 | 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 13 | Go to Step 11 |
9 | Inspect for poor connections at the harness connector of the body control module. 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 13 | Go to Step 12 |
10 | Repair the open in the coil side battery positive voltage circuit of the fog lamp relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | -- |
11 | Replace the fog lamp relay. Did you complete the replacement? | Go to Step 13 | -- |
12 |
Important: Perform the set up procedure for the body control module. Replace the body control module. Refer to Body Control Module Replacement in Body Control Systems . Did you complete the replacement? | Go to Step 13 | -- |
13 |
Does the DTC reset? | Go to Step 2 | System OK |