Hello all - new here... I'll get straight to it - my wifes got a 2002 C230 Kompressor (2-Door) w/about 60000mi. We've never had any real mechanical problems with the car since she's had it - just a wonky suroof and wierd HVAC operation... All maintenance is up-to-date, and I do all that. So - we were driving back to Phoenix from SanDiego on Sunday afternoon - about an hour out of Phoenix, I had the car on Cruise Control @ 85mph (as it had been for the previous 4 hours), and bam - engine starts sputtering out and dies on me - felt just like running out of gas (had over 1/2 tank). So, immediately I assume we might be having an overheating problem (since it was 117 degrees where we were) - and switch the computer display thingy over to show engine temp, which was fine (less than 100 deg C). Popped the hood - had a look around, nothing out of place. No smells (oil, gas, tranny fluid or engine coolant). So, I get back in, and start it up - starts just fine, and off we go... Got back up to speed and made it about another 20 miles and it does the same thing. This time I noticed though that the engine didnt shut off completely, just reduced to idle. I put it in neutral and tried revving the gas, but the tach stayed right at idle - like it wasnt recieving any throttle at all. Very strange... I pulled into a gas station and let it cool off - and checked all fluids and had another look around - nothing. Everything seems fine. So we headed off and it turned off on us 3 or 4 more times until we got home. Seemed as if I needed to turn it off, stop, wait a minute and then it would just start right up (and run rough for a couple seconds - then right itself) and motor on just fine until it decided to shut off again... Very strange indeed...

So, anyone run into this before? I was hoping this was fairly common - but doesnt seem to be so...

It should be noted that the computer is not displaying anything - no check engine light, or any lights for that matter. So, given this, is there any sense in hooking up a scanner, if there are no trouble lights? For many cars (my Honda and Jeep at-least) the computer will display a CEL if the computer has any codes stored. And, if it is worth my time, can I get it scanned at the local parts store (Checker, Autozone, etc) or must it be done by an MB dealer? I'm not really familiar with MB's.

Here is what I think it could be, but I dont know these cars too well:

1) Vapor-lock (it was 117 out) - crappy gas...

2) Clogged fuel filter (would explain why it would only go ~20 miles every time, then have to be shut off, let the fuel pump fill it up, then off again for another 20mi).

3) Bad throttle sensor (assuming these are fly-by-wire type throttle?).

4) O2 sensors were 'overheated' sending ECU bad data, maybe making the car dump into a 'limp' mode of some sort - until they cooled?


Those are just guesses - I'd really like to avoid taking this thing to a dealership - I never pay people to work on my cars (was a mechanic myself for 7 years some time ago..). However, my wife is now driving my Jeep for her daily commute, as she doesnt trust the car - and my lifted XJ gets about 12mpg - so will cost us a fortune if I cant get it fixed soon!

Any help is greatly appreciated!

BTW - Can I pull the codes (if any) myself - wont display on the instrument display thingy?

 

I've had to replace my throttle position sensor due to similar problems - but mine occurred when starting from a traffic light (rather than at steady-state operation).

Does the engine miss at all, or do you simply experience a loss of power?

Hopefully that's your problem - 'cause it's a cheap & easy fix (there is a DIY thread here somewhere for it). Good luck!

 

well this may not be particular to you or mercedes but my girlfriends car was recently doing that (04 dodge neon), and after a few times at the shop they found that the wire connecting the alternator and the battery had corroded itself out from the inside, and in doing so fried two relays anddd something else. she got all that fixed and hasnt had the problem since, but her car was shutting off while doing about 60+ so it sounds similar, no oil problems, no heating problems, nothing, the car would just flat out die and then restart in a few minutes

 

I'm at a loss here, but my guess is the Crank Position Sensor needs to be replaced.

If you haven't changed the fuel filter, that is an easy thing to eliminate. There is a DIY on the board.

 

OK - well the wife took the car to the MB dealer yesterday to have them diagnose the problem, because she swore that her warranty would cover it - warranty expired in May... Anyhow - they said it is a faulty Throttle Position Sensor (Thought it could be...) - that it is giving intermittent and eratic output.

So, new questions:

1) Where is the TPS on these cars? Is it in/on the throttle body as most vehicles - or is it somewhere else (since these are drive-by-wire vehicles)?

2) I cant seem to find these anywhere on-line. Does MB call this something other than a Throttle Position Sensor? Or do they use some other vocabulary?

3) Where can I find one, and how much do they tend to cost?


Thanks.

 

Good news is that the Throttle body is easy to get to. It is just past the MAF sensor. I can't recall seeing what is attached to it, but you can see everything but lifting up the top covers on the drivers side of the engine compartment.

Please do post a DIY once you replace the part.

Ed

 

1) The throttle position sensor is located in the throttle pedal assembly. DIY shouldn't be too hard.

2) When the dealer replaced mine, they used "211-300-08-04 Accelerator". This was the sensor and the pedal together. Glyn has found that in South Africa they can be purchased individually.

3) Don't know the cost. Replaced under warranty. Sorry.

Even at the dealer it shouldn't be more than an hour labor to change out. Good luck!

 

Here

https://mbworld.org/forums/attachmen...ccelerator.pdf

https://mbworld.org/forums/attachmen...0error2-1-.pdf

 

the dealership can actually replace the sensor only here as well, but when you buy the parts from parts dept. they only have one part which is the pedal and sensor together.

 

The factual knowledge and information supplied by the good people on this forum never ceases to amaze me. Thanks Glyn & Frank, for the more detailed info. While I'm not an expert, I try to help when I can (maybe reduce the workload on you guys).

 

I didn't know it was on the pedal. Wow, learn something new about this car everyday.

Ed

 

Thanks Dude!

 

I thought I'd heard you say this before & nearly put it in my post - The OP PMed me. Then I could not find it. You at one time commented that you had to wait for a part from Germany & I could not remember whether that was TPS, TCU or both.

 

Dmatre - Don't sell yourself short - You have provided some excellent posts - we all learn from one another & so the knowledge pool expands.

 

it was the TCU they were ordering.

 

Now if you ever wanted to change to the sport pedals (if you don't have them), this is the time, since the other pedal covers are relatively inexpensive, and the costly one (about $175.00, if I remember right) - the throttle, you'll be ordering anyway.

 

Looks like it's around $175-200.
Easy DIY. Check the Sprint booster thread..
you have to remove the TPS to install the SB.