I read a previous post about the crank position sensor, and makes me wonder what is up with mine now. About 2 weeks ago, wife called and had started the ML, drove about 3 blocks, went in to buy some groceries, and when she went to leave, it would only turn over, and not fire/start. She tried 5-6 times, and nothing. I came down after it sat for about 15 minutes, put in my key and away it went. Ran great since. Now today, I started it, drove it around the block to my front driveway, shut it off and about 20 minutes later, it was dead, same as before. Tried several times, let it sit for 15 minutes, and away it started. I left it idle and after about 5-8 minutes, it just stopped and nothing again for 3-4 tries, let it sit 15 minutes, and away it went. Drove it around the back to my shop and Mercedes mechanic was giving suggestions over the phone. I am the second owner, all records up to date when I got it last August, and he (original dealership) figured the plugs were due, since it has 90,000km (55,000 miles), I pulled the (I think original Bosch) plugs, and the platinum tip was totally gone on all of them! Changed them out with NGK and starts fine 10 times, drove it around some. Could this be MY issue, or is the CPS still suspect to all this?

The M112/113 engines have a real problem with intermittant crank position sensors, we sell SEVERAL of them every day!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

With that being the case should they be replaced based on time or mileage?

My 1999 ML 320 has 108K miles on it and I'd be unhappy if I were out on the road and had a problem with the sensor and had to have the vehicle towed.

Then don't delay! See either Hans in Charleston OR DeDe in summerville!

German Auto Service!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Hans has worked on some of my cars since 1982 when they had something wrong that I couldn't fix.


So should I replace the CPS on my ML due to the mileage or the age?

Edited:

Alldata says:
"NOTE: If the crankshaft position sensor (L5) was replaced, a re-initialization must be carried out with STAR DIAGNOSIS in the menu item control module adaptations."

Is was alldata says accurate? or is the re-initialzation only necessary if the one you are replacing is defective and was in use when it stopped working. In other words if you replace a functioning CPS due to age, mileage or whatever, no re-initialzation is necessary.

I ordered a new one today. the shop manager/mechanic said it is just a simple install. I think in the Alldata, it refers to the specific one, L5 of the two, if you have more than one sensor, and if it is "Crankshaft Position Sensor Function, w/Increment Control", it is a single unit, not 2 seperate ones, it is a simple plug and play. In mine anyway, it is just an install.
It's funny, this dealer/shop said the last one he ordered in and installed was 2 years ago. This is a smaller city, so I am thinking maybe there was only 4-5 of this year and model around. Mine is a '99 ML320.
I will try my OBD2 tonight, see if it shows a stored code for this sensor, and yet it might not , will see.
Thanks again!