DRLs or Auto Headlights Inoperative - keywords bulb daytime front head lamps lights
| Subject: | DRLs or Auto Headlights Inoperative |
| Models: | 2003-2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe |
| 2003-2006 GMC Sierra, Yukon, and Yukon XL |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Owners may comment on the DRLs or the Auto Headlights being inoperative. There will be no DTCs set and all other lights work properly. Before performing any diagnostics inspect the RPO Label for the following RPOs:
T62 (Daytime Running Lamp System - Delete) or
T78 (Headlamps Control - Delete).
A vehicle can be built with either RPOs or both.
Recommendation/Instructions:
It is normal for DRLs to be inoperative if vehicle is equipped with T62.
It is normal for Auto headlights to be inoperative if vehicle is equipped with T78.
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.
