Hi guys, question here about weird cruise control issue. It sometimes works, sometimes doesnt. It shows on display before failure ,,- - km/h´´. Like you are running slow or dont move and wanted to engage cruise control. Then it says - Cruise control and SpeedTronic inoperative. After car restart it starts working. Then after some time - again. Same scenario. I have fresh software update from MB dealer. Issue went away like for 3 months and now again. Then a month or two working and then again. Dealer says without diag, that issue is most probably related to steering column with cruise control switch (together with gear selector - expensive as hell and nowhere on stock new - only used and I am scary that I will buy another sh*t and issue will be same.). I dont think, cruise control selector could be an issue, because switch from cruise control works fine. My suggestion is the speed sensor. It behave like it cannot read speed accordingly and show up this before error ,,- - km/h´´. What do you guys think ? Before I will get to STAR diag. Mz frind has some Chinese sh*t diag. We ran scan and it shows - P0579. I know I will need Star diag first, but your thoughts about this issue ? GLE 400 petrol. Cruise controll is standard without distronic. Pictures added from different car to see how issue look a like.


This I see first, after pull of CC lever.


then this gem appears

You have wheels of very different sizes (new, old) a diagnosis will be perfect

bv9900,
What exactly were you trying to write? You shorthanded the English so much, I have no clue!😳

wheels I have on car, are the same wheels which I have approved in papers from car. Front are 275/45 21” and rear are 315/40 R21.

Do the wheels have the same circumference?Or could it be that some are more worn, or are different brands?I have seen cases, although Mercedes says there is a 3% tolerance.After being sure of this...the correct way is to use the diagnosis

well hope diag will say something good and easy to fix. I have also another potentional suspect - aux battery. Last year I changed main battery because I still had non working start-stop (I dont use it, but I want it to work) mechanic told me to keep AUX battery in a car. It said, its still good. But its actually over 7 years old. What I know, if AUX starts failing, it can affect cruise control with shift selector. So I plan now order and change this small battery anyway. To your answer. All tires are same manufacturer and are same old.

diagnosis then, many possible causes show those symptoms