E250 start stop echo function
My start stop function isn’t working, it’s on and no codes or errors as per tech.
only mods I had was egr software bypass, def system bypassed due to both nox sensors failing.
aux battery was replaced last year by Mercedes when it was still under warranty.
anything else that can cause it not to function?




There is 12 potential parameters that need to be accomplished for ECO stop to work.
Reading coffee grinds has low success ratio.




New batteries never hurt. Your AUX is 1Yr old, how about MAIN ??
ECU won't allow ECO cycle until all conditions are meet including batteries charge status. Old or undercharged batteries don't pass.
The $200 question is to figure if your battery sees charge followed by deep discharge below 12.3v -Or only normal voltage above 12.6V.
The fancy voltage management by ECU and SAM's makes troubleshooting rapidly confusing.

Last edited by CaliBenzDriver; Jun 12, 2021 at 01:13 AM.
replaced main battery
Echo start/stop started working right away
also seems that the car starts slightly faster
suspect had original battery on it from the factory
no production date on it that I could find
plaved a size larger battery h8 instead of h6.
$300 Canadian tax in


