When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hello all. I recently purchased a beautiful 04 E500 wagon. One owner, 114k miles. I’ve been noticing that the backlight for the Thermotronic AC unit does not shut off and stays on all the time. I have checked the car parked in the driveway several times at night and it’s always on. I recently changed the brightness through the secret menu (Function #20) because it was so dim during the day that you could barely read the LCD. Thinking I messed something up I put it back to how it was but the backlight issue is still there.
Any thoughts what the issue might be? I’ve attached pictures for reference.
Check to see if 12 adjusts AC unit illumination if so, unit is in perpetual night mode. Normally rain/light sensor controls lighting conditions and how illumination is affected. May have changed something in diagnostic mode relating to day/night, or inadvertently affected rain/light sensor. Try a reset if this fails worst case scenario may need someone to check using MB diagnostics before jumping to unit replacement.
See if the following resets unit:
- insert key turn to 2 position
- press, hold 2 & 15 simultaneously
- wait until the button lights to stop flashing
- wait a minute or so then start the car engine
Check to see if 12 adjusts AC unit illumination if so, unit is in perpetual night mode. Normally rain/light sensor controls lighting conditions and how illumination is affected. May have changed something in diagnostic mode relating to day/night, or inadvertently affected rain/light sensor. Try a reset if this fails worst case scenario may need someone to check using MB diagnostics before jumping to unit replacement.
See if the following resets unit:
- insert key turn to 2 position
- press, hold 2 & 15 simultaneously
- wait until the button lights to stop flashing
- wait a minute or so then start the car engine
I tried checking 12 but it does not seem to be for the backlight. I also tried the reset but I want able to do it as you can’t press both buttons 2 & 15 at the same time since the are one button and you can only press one at a time.
Reluctant to have someone check with diagnostics, replace unit here are compatible part #s from comparable VIN if you want confirmation I need your VIN. No location given but if you are in USA you can get 2118300685 from ebay @ $35/free shipping. Here are instructions to remove unit for part confirmation and/or replacement.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
