zamax517

Hi folks, hope all are well.


last year my cls550 2009 start blown hot air from rear vents while front blows cold AC air, i make some research and found that heater valve control need to be change, i do it and everything works like charm.

these days the problem start again thinking its the heater again and i do change three ones with no luck, the car still run Cool AC then suddenly the rear vents start to blow hot air while front is cold. I do change the rear AC temperature to Hi then switch it back to Low fix the problem for a while before it starts to blow hot air from rear vents again.


plz anyone help me to figure out whats gets wrong with the car!!!!!!

zamax517

Plz help

nd-photo.nl

Check the interior temperature sensors. 2 of them were broken in my CLS. If you have a STAR/Xentry, or something like an Autel, you can check if they are working properly

1) the one in the overhead control panel > https://mbworld.org/forums/c219/8443...ml#post8812111


2) the one under the steering wheel > https://mbworld.org/forums/c219/8443...ml#post8799942

zamax517

Nope, on diagnosis these sensors didn’t give any codes at all.

nd-photo.nl

Mine didnt give codes if I remember correctly. But check what value they give back.

Mine gave back incorrect values like 68 degrees celsius when it should be 10 degrees or so.

zamax517

Reads of my sensors, i believe something gets wrong with my both (B10/4 & N70b1) (In-car Temperature).

my question is how did you reach and change the sensor under the steering wheel, mine was too narrow and can’t be done.

nd-photo.nl

I have small hands haha, you only need to remove the panel and then snake your hand in. Twist the sensor (I believe it was counterclock wise) and then you can pull it out gently