My wife was driving our '01 E430 4matic from work when out of the blue, she is driving and the car just stops moving. If the car is let to sit and cool down it will go again for a short distance but then stop again. The trans never had any signs of any problems. Could it just be low trans fluid or do you think its kaput? Figures to I was getting quotes on a trans fluid change within the month. The car has 103,000 miles on it.

 

Sounds like the crankshaft position sensor. Do a search here and on Benzworld.org.

 

Here is a more detailed story of the events as I just asked my wife for the whole story.

The engine does not shut off, the car itself just stops moving like the trans died. At idle it does not make any sounds either, sounds pretty normal.

I actually bought the dipstick tool today off ebay for $20.00 so i can at least see if there is any trans fluid in there.

I spoke with my wife again today after she got home from work and she told me the following:

Was stopped at a light, when she was first stepped on the gas to go the car thumped pretty hard then started going normal, but check engine light did come on at this time. She continued down the highway where it was fine, then turned off onto a side street, stopped at another light, the car would then not move, just revving. Turned the car off then back on again, check engine light was now off, car revved but started going. Each time she stopped she had to stop and restart the car to get the car to move again. Each time she did this it the revving would get
worse until it would no longer move.

Also I have already replaced the crankshaft position sensor.

 

Greetings,
I experienced similar symptoms on my E240, as a result of low transmission fluid, caused by the classic "O-Ring" leak. This is apparently a common problem on the E's, where the O-ring seal around the wiring harness going into the 'box leaks. It's relatively cheap to fix, however if left too long, the fluid can push up the harness into the gearbox ECU, and the 'box chews up the clutches etc, then it's time for a re-built/new gearbox, which is expensive.
Check the fluid level, fill if required, and put a large sheet of paper under the gearbox overnight to check for leaks/drips.
Unfortunately, the fact that the 'box is already not engaging gear, or engaging with a bang already indicates a level of damage, and I truly hope that this is not the case.
You will find the harness entering the gearbox on the right-hand side, top, front, and is quite visible.
Good luck...

 

Well, operation trans discovery mission one complete. I just got done checking the TCM, drier in there than the Sahara. I let the car run for about 20 minutes, checked trans fluid, tad lower than the 80 degree mark, obviously not an accurate reading as I cannot tell how warm the trans fluid is and not being able to drive the car I don't think i'll ever get the car to 80 degrees, but close enough for diagnostics that I do have a bunch of oil in there and it is not dry.

When i did first start the car, It would go through all of the gears and when put in drive the car would in fact start to go. Also upon initial startup, the trans had a low whine to it which eventually went away as the car warmed up.The check engine light is now permanently on, which it was not when it first happened. After letting the car run for the 20 minutes or so, i tried to go thru the gears again, this time nothing, and it would also no longer move at all like the trans is in neutral. So.... where do I go from here? Get codes run? What is my best options for doing so?

Another update... I just let the car cool down again for 15 minutes, went back out started the car, cycled slow through all of the gears. I no longer hear any whining. Put it in drive it would start to go again. 2 minutes go by again and back to the car not doing anything, won't move in any gear like it is in neutral once again. I'm going to now let it run a little longer and check fluid again. Read a post about maybe a bad pump, and if the fluid level is above the 80 degree mark than it very well could be.

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to read those codes. OBD will read the generic but not the specific.
Get the correct level,read the codes,get it to someone with an sds scanner.
Could be a bad conductor plate,could be worse,the only way you will find out is properly diagnosing the issue.
My feeling is the pump or the tq converter is shot or some solenoid is not acting nice.