Spend a few more dollars and get the OEM MB part for $165 including shipping from a Mercedes dealer.

1705450305

https://www.getmercedesparts.com/oem...des-parts.html

 

I have the same problem as 'Viper3D' only i went 3 miles then it died. it started 20 minutes later and i drove it home, 3 miles, no problem. today i just moved it 20 feet and it died, put my OBD2 meter on it and it showed no faults! but started 20 minutes later.... would that be the RCM? i have a 2008 coup w/10,000 miles

 

I have the same problem as 'Viper3D' only i went 3 miles then it died. it started 20 minutes later and i drove it home, 3 miles, no problem. today i just moved it 20 feet and it died, put my OBD2 meter on it and it showed no faults! but started 20 minutes later.... would that be the RCM?

 

Does the engine always turn over when you try to start it after it dies ?
If so, then most likely the CPS, if not, then the RCM.

 

Yes it cranks good just no fire

 

[QUOTE=lightninle;876831]Yes it cranks good just no fire per say like it's out of gas

 

80% chance it's the CPS or connection to it.
15% chance it's the fuel pump relay in the RCM.
the other 5% is something else of which I haven't a clue.

Couple of things to try :
Once you tried it and it didn't start, try turning it off, turning the key on to just before start and wait 5 seconds before engaging the starter. If this works, could be a clogged fuel filter or klunky fuel pump. Could also be the no bleed back valve in the fuel filter.

also

if you can catch it where it turns but don't start, try pulling a wire a bit out of a coil pack and see if it is firing the plugs. That will tell us if it is a fuel or ignition problem.

 

Had this problem took it to a "respected" local shop. told me to replace the fuel pump. I declined after reading the posts on this forum. Ordered the RCM from Rock Auto. Tried to start it every day while waiting for part. Engine turned over but wouldn't start. When I got the part took 10 minutes to replace and engine started on first try and have not had a problem since.

 

Im sorry, when I clarified in my last response I should've explained that by saying it would crank I meant that the engine would crank and start up like it should. But that night last week when it stalled, it wouldn't even attempt to crank, although I still had full power throughout the car. However, I was able to jump my car off and it cranked and started up again. Then two times while driving home the engine seemed to lose all thrust. The engine would rev up when I pressed the gas pedal, but it wouldn't push the car. When it came to a stop it stalled out both times. I still had full electrical power each time but the car still wouldn't attempt to crank at all without being jumped off. I got it home that night and each day after that night I went outside and tried to start my car in the driveway and it cranked and started fine. The reason I had it towed was because I was afraid that it would stall out on me again. I haven't found out about any codes yet because I was told it would probably be the end of the week before they could get to my car.

 

Please let us know what they say.

 

[QUOTE=lightninle;876833]

CPS or RCM will cause this. CPS generally throws a code.

 

To anyone who may still be wondering about my car, I just got a call from the dealership where it is at now and they said that their mechanic had checked my car and said he tapped on the PCM box and the car would shut off, so that's what they think the problem is. The mechanic also mentioned that he thinks there is an issue with the junction fuse box because my engine fan would cut on and off when they were checking it. The dealership said that all together to repair that it would be about $3000. However, I made sure to ask about specific codes that they got from hooking it up to a diagnostic computer and the person who called me said they didn't have any listed on the form that she had in front of her. I told them to get the exact codes that the problem reads and to call me back. They said the mechanic is gone and they cant get the codes from him until tomorrow. But the whole thing is just starting to sound a little fishy to me. Does that sound right to you all on here? $3000 to fix that problem? Im really starting to think I just need to get my car out of that dealership or they are going to cost me way more money than I need to pay

 

Tapping in that area he may have also hit the RCM. Which by the way will cause your engine cooling fan to spin up if the engine control relay is bad.

You REALLY need to get your car outta there!!!!!

 

Plus 1, get that car outta there!


.

 

Plus 2! Send your RCM to tighed1 and quit freicking around. You DO NOT need or want the dealer. Get it home, pull out the RCM and send to tighed1. No tools necessary!

 

I would imagine that some Chrysler dealerships routinely insist on replacing the PCM (which supposedly rarely fails) for $3,000 while actually knowing that it isn't the problem at all. They can charge you $2500+ for the part, plus installation labor and programming (which most independent shops won't be able to do). Meanwhile, they can probably get a new PCM from Chrysler for less than $1500 (maybe a lot less). They can get a new RCM for around $100 to actually fix the problem. The customer won't suspect any foul play because the car now runs perfectly, and won't be too upset with the dealership because most of the cost was in the part (the PCM) and not diagnostics and repair labor. Heck, the dealership might even get away with just changing the RCM and never touching the PCM. Cha-ching!

 

I'm guessing that there is only one manufacturer of the RCM - Stribel/Flextronics. Mercedes doesn't manufacture them. The stock photos for any after market supplier typically seem to have the Stribel logo on them just like the OEM part. That said, the RCM is one item where you probably couldn't do worse then "OEM" if other manufacturers offered a product. But at $161.60 the link you provide is still a decent price; you can probably have one (for example, Standard Motor Products) delivered for just over $140 from Rock Auto.

 

Stop with the idea of buying a new RCM. It will eventually fail the same way. Listen to tighed1. Get the car outta there. send him the danged thing, and get it fixed right. Get your flippin car outta there. Quit wasting time and money with these dealerships. They don't have a clue about these cars.
Listen to these cats. They know what they are talking about!!!

 

I think that the later RCMs can be considered to be OK. The problems arose in the early years of these, I think that as the problems arose and the solution found any company that continued to make them in a faulty manner would have been dropped by Mercedes.
The problem has been known on the Mercedes forums since 2006.

 

I talked to the dealership again, and I am definitely not letting them work on my car. When I asked about specific codes, they said that they didn't have any from when they did the diagnostic check. The woman on the phone kept trying to avoid my question about them actually hooking it up to a computer, because I don't think they did. Im pretty sure their mechanic just took a quick look under the hood and took his best guess. I'm having my car towed back home tomorrow before they mess it up for good