My '04 Coupe has less than 7000 miles on it and hasn't worked for a couple of months and is, in fact, only adept at being a bump in the yard. I am now desparate for ideas on what to look at next. It has all of the symptoms (and maybe more) of a bad RCM. However, the RCM solder joints all look excellent and are well wetted with solder but just to be sure, I re-melted the ones shown to go bad. Since it fails when cold, it's not logically the CPS but just to be sure I changed that with no improvement resulting.
The "maybe more" symptoms are that the engine fan motor roars to life when the key is turned to start and the radio turns on! Is this at all normal? Does it give anyone any clues as to what to do next?
I had it carried to the only Chrysler/Dodge dealer a couple of months ago but he was lost as it started then and ran for a few days afterward and the computer diagnostic said that everything was fine. I am now thinking of having it carried to a Mercedes dealer as the only thing left to do. Any other ideas? Anything other than scrapping it will be appreciated.

 

If you are still under the 8 year emission warranty u need to get it checked, had one with a defective ecu that did this! Rad fan came on, radio, all lights worked just would not turn over engine, but then for no reason would start, I assume you have checked are replaced battery, checked connections

 

Start by getting a new car battery. Also, the fan can be turned to the off position as well as the radio. Neither should work when in the off position when starting the engine. Good luck! OK, if you meant the engine cooling fan, then I haven't a clue.

 

Be very careful of the number of times you try to start the car. There is a limited number of tries before the computer 'thinks' it is being stolen and fries the ECU. I would also check the RELAY contacts on the RCM, as some of them have badly burned the contacts to the point of it not starting. Good luck, get a new battery and clean the posts/clamps, and keep us posted!

 

i did not know this... fries the ecu?!!?!??!

 

Not quiet! More like a lockout

 

Can someone show the reference to this in either the Owners or Service Manual...???

I've seen this statement come up quite a few times, but can't seem to get it confirmed.

Also, if this happens, is the fix to replace the ECU, or can it be reset via the Star System...???

Someone had asked Rudy at Needs, and he indicated he had never heard of this...!!!

Inquiring minds would like to know...

Thanx...

 

I hadn't seen this myself but there are so many references in this forum I thought it was set in stone. OK, maybe I am incorrect by reposting this but again, it is said in so many posts. Hope you get her running again!