Auto Headlamp/DRL not functioning

Discussion in 'Technical write ups & Installation Guides' started by thndrwlf, Apr 6, 2019.

  1. thndrwlf

    thndrwlf New Member

    Messages:
    1
    Likes Received:
    0
    Joined:
    Apr 4, 2019
    2006 Chevy Tahoe 5.3L base trim

    I recently failed the State safety inpection in Virginia because my Daytime running lamps don't come on. In diagnosing the issue I found that the DRL do light when the ambiant light sensor is covered or at night for a 30 second delay when using the key fob to unlock the doors. I also resently installed a new headlamp control switch in the dash to eliminate that as an issue. When I got the truck the dash light dimmer did not function so I installed a junk yard part. I checked the wires coming from the BCM and they all work and gets a signal when you turn the headlamp switch to the off position agains the spring from the auto position (AHL/DRL defeat). I also observed that the auto headlamps don't seem to work either, and the dash lights are lit when the truck is started, and the message center text is dim and difficult to read during the day. I also noticed that there are no warning chimes for seatbelt warning, door adjar with key in ignition, or headlamp left on. There is an aftermarket radio installed that apears to have been profesionally installed. The only conclusion I can draw at this point is a bad BCM. The vehicle was once owned by The Virginia Department of Game and Inland Fisheries so I am not sure when they removed their accessories such as radios and lightbars that they messed with the factory wiring or changed the programing somehow.

    I was wondering if anyone might have some insight or programming instructions for the Auto headlamp/DRL feature.