Pinpoint Test S: The Fog Lamps Are On Continuously

Fog Lamps

Pinpoint Test S: The Fog Lamps Are On Continuously

Normal Operation

The Steering Column Control Module (SCCM) monitors the fog lamp switch position by sending a voltage signal to the headlamp switch. When the fog lamp switch is engaged, the voltage signal is routed to ground indicating a request for the fog lamps.

The SCCM (Steering Column Control Module) sends a message to the Body Control Module (BCM) over the High Speed Controller Area Network (HS-CAN), indicating the fog lamp switch position. When the BCM (Body Control Module) receives input from the SCCM (Steering Column Control Module) indicating a request for the fog lamps, the BCM (Body Control Module) provides ground to the fog lamp relay (integrated into the BCM (Body Control Module) ). When the fog lamp relay is energized, voltage is routed to the fog lamps.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Headlamp switch

- SCCM (Steering Column Control Module)

- BCM (Body Control Module)

PINPOINT TEST S : THE FOG LAMPS ARE ON CONTINUOUSLY

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

S1 CHECK THE FOG LAMP SWITCH PID

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: SCCM (Steering Column Control Module) DataLogger.

- Monitor the SCCM (Steering Column Control Module) fog lamp switch PID (FOG_F_SW) while turning the fog lamp switch on and off.

Does the PID indicate the fog lamp switch is operating correctly?

Yes
GO to S4.
No
GO to S2.

S2 CHECK THE HEADLAMP SWITCH

- Ignition OFF.

- Disconnect: Headlamp Switch C205.

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: SCCM (Steering Column Control Module) DataLogger.

- Monitor the SCCM (Steering Column Control Module) fog lamp switch PID (FOG_F_SW).

Does the PID indicate the fog lamp switch is on?

Yes
GO to S3.
No
INSTALL a new headlamp switch. REFER to Headlamp Switch . TEST the system for normal operation.

S3 CHECK THE FOG LAMP REQUEST INPUT CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.

- Disconnect: SCCM (Steering Column Control Module) C2414A.

- Measure the resistance between the headlamp switch C205-5, circuit CLF21 (GY/VT), harness side and ground.






Is the resistance greater than 10,000 ohms?

Yes
GO to S6.
No
REPAIR circuit CLF21 (GY/VT) for a short to ground. TEST the system for normal operation.

S4 CHECK THE BCM (Body Control Module) FOG LAMP INDICATOR OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: BCM (Body Control Module) C2280A.

- Ignition ON.

Do the fog lamps continue to illuminate?

Yes
GO to S5.
No
REPAIR circuit CLF12 (BN/YE) (between the BCM (Body Control Module) and the headlamp switch) for a short to voltage. TEST the system for normal operation.

S5 CHECK THE BCM (Body Control Module) FOG LAMP OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: BCM (Body Control Module) C2280E.

- Ignition ON.

Do the fog lamps continue to illuminate?

Yes
REPAIR circuit CLF12 (BN/YE) (between the BCM (Body Control Module) and the fog lamps) for a short to voltage. TEST the system for normal operation.
No
GO to S7.

S6 CHECK FOR CORRECT SCCM (Steering Column Control Module) OPERATION

- Disconnect all the SCCM (Steering Column Control Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the SCCM (Steering Column Control Module) connectors and make sure they seat correctly.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new SCCM (Steering Column Control Module). TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

S7 CHECK FOR CORRECT BCM (Body Control Module) OPERATION

- Disconnect all the BCM (Body Control Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the BCM (Body Control Module) connectors and make sure they seat correctly.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new BCM (Body Control Module). TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.