[jlawrence]

I'm having the same issue, but it's affecting my right rear door instead and has been going on for nearly two years. I was also told that it might be the Body Control Module, but since the actual impact of the problem is minor and the cost was high to replace it, I haven't bothered. But get this, I live in North Dakota, and the problem goes away completely all winter, only to re-appear in the spring. I can only assume that it's related to temperature/humidity, and once the temp is down in the teens and below zero, everything returns to normal, and the "door is ajar" message only appears when I actually leave the door open. Once the temp is back up above freezing, I'm back to ding-ding-ding "door is ajar" again. Any chance that sparks an idea or two on possible causes?

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2003 Silverado 1500HD Crew Cab