96' C220 Diagnostic Fail Code P0505 Help
09-08-2007, 10:38 AM
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Join Date: Sep 2007
Location: Toronto, Ontario
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2004 E320, 2001 CLK320, 2001 C320
Idle control P505
Hi there. That code USUALLY means the throttle body has a problem. This era of C Classes are prone to problems with them and the engine wiring harnesses breaking down. The throttle body problem is USUALLY the insulation on the wiring breaking down and shorting out. If this is the case as well as having the check engine light on and the code P505 you will probably have other symptoms.
1] Lumpy idle when you first start up in the morning and a tendancy to stall out if you put it in gear too soon.
2] Cruise control stops working.
3] notice an occasional misfire which sometimes clears if you stop and restart the engine.
A new Benz throttle body is about $2,000, but there are companies that rebuild them or supply replacements. Cant say how good any of them are as I have not tried them yet, but as my throttle body is on the way out I will be trying various options over the next few months.
One thing I would suggest though is dont rely on the code and peoples opinions alone, thats usually the problem but its a lot of money to spend if its something else causing the problem. Personally I would take it to a reliable Benz tech and have them diagnose it 100% before you throw parts at it. It should only be about $150-$200 to get that done and you may just find a simple problem that is causing the code. I doubt it, and wish you luck but I think you probably do have the same throttle body problems a lot of Benz owners have suffered already.
1] Lumpy idle when you first start up in the morning and a tendancy to stall out if you put it in gear too soon.
2] Cruise control stops working.
3] notice an occasional misfire which sometimes clears if you stop and restart the engine.
A new Benz throttle body is about $2,000, but there are companies that rebuild them or supply replacements. Cant say how good any of them are as I have not tried them yet, but as my throttle body is on the way out I will be trying various options over the next few months.
One thing I would suggest though is dont rely on the code and peoples opinions alone, thats usually the problem but its a lot of money to spend if its something else causing the problem. Personally I would take it to a reliable Benz tech and have them diagnose it 100% before you throw parts at it. It should only be about $150-$200 to get that done and you may just find a simple problem that is causing the code. I doubt it, and wish you luck but I think you probably do have the same throttle body problems a lot of Benz owners have suffered already.
