Q: I have a 2009 Chevrolet Malibu LT. Since May, my interior lights have been going on and off sporadically. When I go over bumps, they flicker. In the morning on my way to work, they are completely off.

Then around lunchtime when it's hot, they are on - all day and night until I park it in a cool location. When it's 65 degrees or less outside, the lights are off. I feel like it's heat-induced, but am not sure how to fix the problem.

A: Since the illuminated entry system controlled by the body control module, or BCM, turns on the interior lights when a door switch is activated, I'd focus on the door switches.

When they close, the circuit in the BCM is grounded and the lights illuminate. Perhaps heat is expanding an involved component just enough to electrically trigger the switch.

Check that the dimmer switch is not rotated to the point of turning on the lights and you could try switching the dome light to the "off" position. The BCM should turn off the courtesy lights after 20 minutes.

Paul Brand, author of "How to Repair Your Car," is an automotive troubleshooter, driving instructor and former race-car driver. Write to him at: Star Tribune, 425 Portland Ave. S., Minneapolis, Minn., 55488 or via email at paulbrand@startribune.com.