Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Front Fog Lamp Relay Control | B2530 02, 3 | B2530 05, 3 | B2530 05, 3 | -- |
Front Fog Lamp Voltage Supply | 1 | 1 | 1 | -- |
Front Fog Lamp Switch Signal | 2 | 2 | 2 | -- |
Front Fog Lamp Relay Ground | -- | 1 | -- | -- |
Fog Lamp - LF Ground | -- | 1 | -- | -- |
Fog Lamp - RF Ground | -- | 1 | -- | -- |
Fog Lamp Switch Ground | -- | 2 | -- | -- |
1. Front Fog Lamps Malfunction 2. Fog Lamp Switch Malfunction 3. Fog Lamp Indicator Malfunction | ||||
Circuit/System Description
When the fog lamp switch is placed in the ON position, ground is applied through the fog lamp switch signal circuit at G300 to the body control module (BCM). The BCM applies battery voltage through the fog lamp relay control circuit to the coil side of the fog lamp relay. Battery voltage is applied at all times from the FOG LAMP fuse to the switch side of the fog lamp relay. When the relay coil is energized, the relay switch contacts close and allow battery voltage to be applied from the FOG LAMP fuse, through the relay switch contacts, to the fog lamps. Ground for the fog lamps is applied at all times at G101 for the left fog lamp and G102 for the right fog lamp. G102 also serves as ground for the coil side of the fog lamp relay.
Reference Information
Schematic Reference
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Ignition ON, observe the scan tool front fog lamp switch parameter while pressing and releasing the front fog lamp switch. The reading should toggle between ACTIVE and INACTIVE.
| ⇒ | If the reading does not change between the commanded states, refer to Fog Lamp Switch Malfunction. |
Circuit/System Testing
Fog Lamp Switch Malfunction
- Ignition OFF, disconnect the harness connector at the fog lamp switch.
- Test for less than 1 ohm of resistance between the ground circuit terminal A and ground.
- Ignition ON, verify the scan tool front fog lamp switch parameter is INACTIVE.
- Install a 3A fused jumper wire between the signal circuit terminal C and the ground circuit terminal A. Verify the scan tool front fog lamp switch parameter is ACTIVE.
- If all circuits test normal, test or replace the fog lamp switch.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If not the specified value, test the signal circuit terminal C for a short to ground. If the circuit tests normal, replace the BCM. |
| ⇒ | If not the specified value, test the signal circuit terminal C for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
Front Fog Lamps Malfunction
- Ignition OFF, disconnect the fog lamp relay.
- Test for less than 1 ohm of resistance between the relay coil ground circuit and ground.
- Connect a test lamp between the fog lamp relay control circuit and the relay coil ground circuit.
- Command the fog lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- Verify that a test lamp illuminates between the relay switch B+ circuit and ground.
- Disconnect the harness connector at the Inoperative fog lamp.
- Test for less than 1 ohm of resistance between the inoperative fog lamp ground circuit terminal B and ground.
- Connect the harness connector at the inoperative fog lamp.
- Connect a 15A fused jumper wire between the relay switch B+ circuit and the relay controlled output circuit. Verify the fog lamps are activated.
- If all circuits test normal, test or replace the fog lamp relay.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp does not illuminate, test the relay switch B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the relay coil B+ circuit fuse is open, test the relay controlled output circuit for a short to ground. |
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the fog lamps do not activate, test the relay controlled output circuit for an open/high resistance. If the circuit tests normal, test or replace the inoperative fog lamp. |
Fog Lamp Indicator Malfunction
- Ignition OFF, disconnect the harness connector at the fog lamp switch.
- Test for less than 1 ohm of resistance between the ground circuit terminal A and ground.
- Connect a test lamp between the fog lamp relay control circuit terminal B and ground.
- Command the fog lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If all circuits test normal, test or replace the fog lamp switch.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp is always ON, test the control circuit terminal B for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp is always OFF, test the control circuit terminal B for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Front Fog Lamp Relay Switch B+ | 1 | 1 | 1 | -- |
Front Fog Lamp Relay Control | B2530 02 | B2530 05 | B2530 05 | -- |
Front Fog Lamp Voltage Supply | 1 | 1 | 1 | -- |
Front Fog Lamp Switch Signal | 2 | 2 | 2 | -- |
Front Fog Lamp Relay Ground | -- | 1 | 1 | -- |
Fog Lamp - LF Ground | -- | 1 | 1 | -- |
Fog Lamp - RF Ground | -- | 1 | 1 | -- |
Front Fog Lamp Switch Ground | -- | 2 | 2 | -- |
1. Front Fog Lamps Malfunction 2. Front Fog Lamp Switch Malfunction | ||||
Circuit/System Description
When the front fog lamp switch is placed in the ON position, ground is applied through the front fog lamp switch signal circuit at G300 to the body control module (BCM). The BCM applies battery voltage through the front fog lamp relay control circuit to the coil side of the front fog lamp relay. Battery voltage is applied at all times from the FOG LAMP fuse to the switch side of the front fog lamp relay. When the relay coil is energized, the relay switch contacts close and allow battery voltage to be applied from the FOG LAMP fuse, through the relay switch contacts, to the front fog lamps. Ground for the front fog lamps is applied at all times at G101 for the left front fog lamp and G102 for the right front fog lamp. G102 also serves as ground for the coil side of the front fog lamp relay. For more detailed information concerning fog lamp operation refer to Exterior Lighting Systems Description and Operation.
Reference Information
Schematic Reference
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Ignition ON, observe the scan tool front fog lamp switch parameter while pressing and releasing the front fog lamp switch. The reading should toggle between ACTIVE and INACTIVE.
| ⇒ | If the reading does not change between the commanded states, refer to Front Fog Lamp Switch Malfunction. |
Circuit/System Testing
Front Fog Lamp Switch Malfunction
- Ignition OFF, disconnect the harness connector at the front fog lamp switch.
- Test for less than 1 ohm of resistance between the ground circuit terminal A and ground.
- Ignition ON, verify the scan tool front fog lamp switch parameter is INACTIVE.
- Install a 3A fused jumper wire between the signal circuit terminal C and the ground circuit terminal A. Verify the scan tool front fog lamp switch parameter is ACTIVE.
- If all circuits test normal, test or replace the front fog lamp switch.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If not the specified value, test the signal circuit terminal C for a short to ground. If the circuit tests normal, replace the BCM. |
| ⇒ | If not the specified value, test the signal circuit terminal C for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
Front Fog Lamps Malfunction
- Ignition OFF, disconnect the front fog lamp relay.
- Test for less than 1 ohm of resistance between the relay coil ground circuit terminal 85 and ground.
- Connect a test lamp between the front fog lamp relay control circuit terminal 86 and ground.
- Command the front fog lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- Verify that a test lamp illuminates between the relay switch B+ circuit terminal 30 and ground.
- Disconnect the harness connector at the Inoperative front fog lamp.
- Ignition OFF, test for less than 1 ohm of resistance between the inoperative front fog lamp ground circuit terminal B and ground.
- Connect the harness connector at the inoperative front fog lamp.
- Connect a 15A fused jumper wire between the relay switch B+ circuit terminal 30 and the relay controlled circuit terminal 87. Verify the front fog lamps are activated.
- If all circuits test normal, test or replace the front fog lamp relay.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp does not illuminate, test the relay switch B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the relay coil B+ circuit fuse is open, test the relay controlled circuit terminal 87 for a short to ground. |
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the front fog lamps do not activate, test the relay controlled circuit for an open/high resistance. If the circuit tests normal, test or replace the inoperative front fog lamp. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
