Pinpoint Test T: The Front Fog Lamps Are On Continuously

Fog Lamps

Pinpoint Tests

Pinpoint Test T: The Front Fog Lamps Are On Continuously

Refer to Wiring Diagram Set 86, Fog Lamps for schematic and connector information. Diagrams By Number

When the headlamp switch is placed in the PARKING LAMPS or HEADLAMPS ON position and the knob is pulled to the first detent, the headlamp switch provides voltage to the front fog lamp relay coil. Voltage is provided to the front fog lamps when the front fog lamp energizes.

- DTC B2254 (Front Fog Lamp Switch Failure) - an on-demand DTC that sets when the GEM detects a short to voltage from the fog lamps voltage supply circuit.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Headlamp switch
- GEM


PINPOINT TEST T: THE FRONT 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.

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T1 CHECK THE FRONT FOG LAMP RELAY OUTPUT


- Ignition OFF.
- Disconnect: Front Fog Lamp Relay.
- Ignition ON.
- Do the front fog lamps continue to illuminate?

Yes
GO to T2.

No
GO to T3.

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T2 CHECK THE GEM


- Ignition OFF.
- Disconnect: GEM C201b.
- Ignition ON.
- Do the front fog lamps continue to illuminate?

Yes
REPAIR the fog lamp relay output circuit for a short to voltage. TEST the system for normal operation.

No
GO to T5.

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T3 CHECK THE FRONT FOG LAMP RELAY


- Ignition OFF.
- Substitute a known good relay.
- Ignition ON.
- Do the front fog lamps continue to illuminate?

Yes
REMOVE the known good relay. GO to T4.

No
REMOVE the known good relay. INSTALL a new front fog lamp relay. TEST the system for normal operation.

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T4 CHECK THE HEADLAMP SWITCH


- Ignition OFF.
- Disconnect: Headlamp Switch C205.
- Ignition ON.
- Do the front fog lamps continue to illuminate?

Yes
REPAIR circuit 15-LD1 (GN/YE) for a short to voltage. TEST the system for normal operation.

No
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.

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T5 CHECK FOR CORRECT GEM OPERATION


- Ignition OFF.
- Disconnect all the GEM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the GEM 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 GEM. REFER to Multifunction Electronic Modules Service and Repair. 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.

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