I had the service vehicle soon light come on in my 04 Monte Carlo LS a few months back, I recently had it scanned and the scanner came up with:

B2648 Ambient Light Sensor Circuit High

I'm wondering if anyone is aware of something that may be triggering this error to show up other than a faulty ambient light sensor? I should also mention that the ambient light sensor is still working properly as my daytime runners come on fine, headlights switch on when it gets dark, and the dash lights also turn on when its dark. This is leading me to believe something else may be triggering this error...at least that's what I'm hoping so I don't have to tear apart my entire dash to replace this sensor

 

My service vehicle light is on and my car is always in night time mode. Drl do not function and my interior lights are dimmed. I also scanned the same code. 2000 pace car.

 

Fortunately mine is not in night mode all the time...the other odd thing is that sometimes the service vehicle light will just turn off without me making any changes. I'm starting to wonder if there is a short somewhere causing this error to display.

 

Turned out to be bad bcm, headlight relay and ambient sensor. Had to bring it to the dealer. Cost me $600.00

 

Ouch, thats sucks man. Thanks for the info.