2001 Jimmy automatic Headlights

rodlech

Hi all
The automatic headlights on our 2001 Jimmy stopped working. Headlights turn on with switch but not automatically.
Thanks in advance for any help

thecardoc3

Start by connecting a scan tool that can communicate with the body computer. You first need to check for any trouble codes. Then see what live data shows in regard to the ambient light sensor at the top of the dash. The third thing to do is see if there is a bi-directional control command to make the body computer command the headlamp relay to turn on. The headlight switch sends power to that same relay when it is used to turn the headlights on, so the problem is related to the body computer, it's inputs or output capabilities.

rodlech

Thanks for the very detailed reply!! Where would I find the headlight relay/module? Or is that the DRL relay in the fuse box under the hood?

thecardoc3

The headlamp relay is in the under hood fuse block, but it has to be OK itself because you can turn the headlights on with the regular switch. As I said above you need a professional level scan tool to do the diagnostics efficiently. The Body computer is responsible for the automatic headlight control.

The description for the DRL relay location says that it is "taped to the body harness near breakout for rear washer hose". I suspect that's in the RH inner fender area, but would have to search for a better description to be sure.

rodlech

Thank you very much