Hey solnyc2,

Okay so following from your feedback:

RCM - do not order from ebay, I haven't seen any new ones for sale, only used ones that are probably shot!

You're best bet is to order one through Mercedes, in my experience this is a lot cheaper than going to Chrysler. See what Mercedes quote you. I know you can get one in the UK for £109 and Chrylser wanted £170 for exactly the same part!

I used a fault code reader to clear the code, but I did the battery disconnect too for good measure + I had added a new exhaust and CAI so I wanted to reset the ECU as fully as possible.

I have seen new air pressure valves (although they are called air check valves - but the 2 metal valves in any case) on ebay for about $65 each - but as I say, I've not heard of these going wrong.

I would say the RCM is the culprit, if you have an older Crossfire like an 04 then to me its the next logical option after the battery disconnect - which doesn't cost anything and may well solve it for you.

I hope this helps - I'm no expert, but I had the same issue and it was driving me insane, I knew my pump was fried so that was the first port of call and it solved the issue.

Good luck with it

Regards

AR