Assuming you have the 722.6 on that 99 ML

Just curious, did you get a Genuine Mercedes new in the box sensor from the MB dealership parts counter? Lots of counterfeits running around on eBay and the internet in general.

Not shilling for MB, just had a personal experience with this with a Bosch aftermarket crank position sensor, that would randomly shut down my OM606. Dealer parts counter sensor worked like a champ.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

It was an OEM part. These parts are usually reliable.

Interesting with your Bosch part as I believe Bosch makes these for Mercedes. They just put on the Mercedes logo etc.