GM Service Manual Online
For 1990-2009 cars only

Fog Lamps Inoperative - keywords BCM lamp light switch

Subject:Fog Lamps Inoperative

Models:2002 Cadillac Escalade and Escalade EXT
2000-2002 Chevrolet Avalanche, Suburban and Tahoe
1999-2002 Chevrolet Silverado
1999-2002 GMC Sierra
2000-2002 GMC Yukon, Yukon XL, Yukon Denali



The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

The following vehicles listed above may have a concern where the fog lamps may be inoperative from the switch, but can be commanded on with the Tech II. After following normal diagnosis, you may have replaced the BCM with no correction of concern.

Recommendation/Instructions:

The Fog lamps will not activate unless the BCM sees a park lamp input on circuit 2409 to the BCM. Diagnostics & wiring schematics make no mention of the circuit 2409 used for fog lamp. Check the INT PRK fuse, circuit 2409 wiring, connectors & inspect BCM connector C2 pin B6 for battery voltage with headlamps on. Repair as needed.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.