So, theres either a problem with the relay or the integrity of a trace on the board. Some say that it could be vibration, heat or poor soldering. I was wondering if it is heat related, and if so, would posssibly removeing the bottom engine shroud allow for more cooler air ciculation in and around the engine compartment. I have an 07 and this problem maybe right around the corner for me.

 

A bad crank sensor will allow the engine to turn over when turning the key to start. The relay control module in my experience, the car's accessories....radio, a/c, lights all worked but the engine would not turn over ! Hope this helps !

 

Bump to keep this thread where people can find it....

And a big thank you!!! I should have checked these forums first. I searched for days and found mostly posts that ended in "Problem fixed... car sold!!!"

My wife loves her Xfire and selling it was not really an option. Thank you so much for this simple solution.

To Review:
Cranks but wont start = Crank sensor
Wont Crank at all = Relay Control Module

Note: Dying while driving can also ba a symtom of this problem. If the fuel pump cuts out = no fuel = car does not run.

 

Hey everyone. I had the dreaded "Won't start" problem and thanks to all the treads, I ordered the RCM from Mercedes Benz and installed it in two minutes. Cranked it up and no problems. Best $200 bucks I ever spend on repairs because I know the dealer would have charged me at least double. Does anybody know if someone can fix the bad one. I've been reading that it can be resoldered so just wondering if there is anyone out there that can do it.

 

Went to the local dealer last week to resolve my no start issue since the XF is still under warrenty. Informed dealer to check fuel pump relay and showed them these posts. After two hours and being presented a bill for $98.50 (Tech found code 2071-08 for skreem module and stated no problem at this time.) Dealer stated they could not replace the RCM since they could not verify that it was the problem. He stated that maybe the electronics might have to be replaced(cost $3000) and could not verify if they would be covered under my warrenty (Chrysler Max). Said if problem occurs again, to bring back XF . Moral of story, I am going to order the RCM and replace it myself. Hope it solves the no start problem. If not, at least I know that it was not the problem. Where is the best place to get this part? Thanks, without this forum, I could possibly be $3000 lighter in the bank account.

 

Thanks so much... I finally can take my car to the dealer and show him this.. Yes, a woman the first time, second time with hubby.. basically telling the guy that's not an acceptable answer and him whining to give him a good job done on the customer survey... WHAT!!! You did nothing to my car other than tell me yet once again "can't duplicate the problem" Well, seem like I'm going to MB anyway.. Yes, I think this should be a RECALL.

Thanks again

Sue

 

Hey ya'll. Was just inside of the relay control module today and noticed that three of the relay coils were darker than the other two. Should have checked what each relay was for while I had it all apart. Will check when I do my https://www.crossfireforum.org/forum/tsbs-how-articles/37347-how-horn-all-time.html
mod on my other Crossfire. May point to potential problem with the RCM.

 

Yo Wolfie28. If you wanta send me your "bad" relay control module I'll look it over for you.

 

my car doesn't start.... so this ralay module part is not cover under warranty??? seems that way based on what I see here so far but I just wanted to make sure.

 

Should be covered.

 

thanks tighed1

 

Ok, third time posting this. Hope you got it!
Meanwhile if the car stalls again open the hood and on the passenger side right next to the battery is a black plastic box. If you open the box (by sliding the tabs located on the top of the box) you will see a couple of circuit cards closest to the battery side and then there's a smaller black plastic case that is on the engine side of the box (furthest from the battery side.). This is the relay control module. Smack it around a little and try to restart the car. Might work, might not.
Let us know if it works.

 

Hey,
Need help quick
Is this crank sensor a do-it-yourselfer?
I know nothing about what's under the hood of a car but I know when I had another sensor put in by the mechanic it looked as simple as could be.
I just spent $1800 dollars at the dealer and still have this problem.
It looks like this sensor costs about $200 on the one-site I looked at.
Does anyone know where to get it cheaper?
Thanks a bunch

 

IF you read through all of the posts on this issue you will discover that if your car dies and DOES crank (but does'nt start) - The Crank Position Sensor is most likey your problem.
If the car dies and DOES'NT crank - The Relay Control Module is likely the problem.
You said that your car doesn't turn over. In that case I would suspect the RCM. Try slapping the RCM around a bit, un-install / re-install it and see if the car will start.
Did it?

A good thread for the CPS is here.

 

The reason warranty isn't covering this is that the problem can't be duplicated by the dealer.

The dealer gets paid by the manufacturer or the warranty company, and more than they usually charge you for out-of-warranty repairs. There's a "book" -- or computer program these days -- that tells the dealer how many hours of labor it takes to replace something. That's what they get paid, plus difference in retail and wholesale on the parts.

In my case, the RCM failed after some hot driving. Stopped for 10 minutes at Home Depot and it wouldn't start back up. Went back and shopped for another 45 minutes and it started no problem.

If I had taken it to a dealer they would have said there was no problem.

The key would be to take it in after driving hard for about an hour, turn it off, then ask the service manager to come out and try to start it.

Got my replacement from the MB dealer for $180 or so. He said these things fail all the time because of the engine heat melting solder.

P.S. I'm sending my old RCM to tighed to see if he can determine what's happening.

 

I had the relay control module replaced by the dealer. It was replaced under the 3 yr./36000 bumper to bumper warranty. I also had them fix a oil leak from the rocker cover. This one made me laugh because the dealer said that only someone who keep the engine that clean would spot such a small leak. They didn't question the leak but did have to prove to themselves that the Relay Control Module (RCM) really needed to be replaced. It took a week but it is done. The car runs great.

I was just wondering how often the RCM needs to be replaced? Has anyone had to replace it twice?

So far I have had all the standard fixs -- treansmission leak, oil leak and the RCM. Oh I had the dreaded panic button does not work.

This may interest some of you. The only Chrysler product dealer left in my town is a Jeep dealer.

 

the mystery no start happened to my black one at 440 miles. rcm replaced (with major props to this thread/site...brought in a couple of pertinent pages to the dealer, who is great btw) and no problem since. must be a manufacturing flaw. covered under warranty but they did check a couple of systems to be sure it was the rcm.

 

I would think video of the issue would be sufficient means to mandate warranty work. So if you have a spare recorder lying around take it with you.

 

I'll bet tighted tells you that the solder is cracking due to vibration and skimpy amounts of solder being used in manufacturing.

I REFUSE to believe that it gets hot enough under the hood to melt solder - that occurs at just over 370 degrees.

 

I would also add that we have had a lot of headlight flashers fail over the years. The ones we used until the late 90's used two soldered-in relays and a 555 timer chip to drive the relays. Solder was always cracking around the relay sockets due to the weight of the relay/socket assembly "working" on the solder joints due to the vibration under the hood.

I have seen transistors unsolder themselves in high power PA assemblies, due to the heat generated in the transistor.