Armanidog

My 2017 GLS550 runs about 800 RPM with AC on and about 500 RPM with it off. This is in Phoenix with outside temperature at 110 degrees. Also have a 2018 AMG GLE coupe and it runs about the same RPM's with AC on and with it off at the GLS.

jerome8283

Thanks guys. It appears this is normal as you all point out. Chuck123 please let us know if you find out anything different.

jehadfh

i have ml400 2015 i notes same issue when car in sun but in night idle is normal and ac on i try put some cold water to air sensor and it solved. the proplem in sun air sensor give higher tempreture so idle go up 4 tick