I dont understand any of the hard fault 02 sensor or changing the pcm car runs great and light off only comes on if add gas sometimes

 

I don't understand what your problem, situation, or issue is. I am sure most agree with me. Please try to restate?


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Sorry new to this. What I need to know is do I need to change the pcm and 02 sensors if car running so good? My dad gave me car and I am a 54 year old woman with no car knowledge. I love the car but feel like dealership trying to rip my elderly father off they even said 2 of tire pressure senors failed and had to change pcm for that. I just am trying to learn all I can before I put lot of money in car. It is a 2004 with only 38000 miles on it and kept in garage it still looks brand new

 

Well, you have already learned the most important lesson about the car : AVOID DEALERSHIPS !!!
Best bet for you is buy a cheap OBDC code reader and reset all codes, then see if they come back.
Also use the search feature on this forum, 99% of all possible failure/fixes are documented here.

 

1. Remove car from Dealership!
2. Take car to Advance Auto, Auto Zone, O'Reillys or NAPA car parts store. Tell them occasionally you get a Check Engine Light on and would like for them to check the diagnostic trouble codes (DTC). Ask them for the exact numbers, DO NOT ACCEPT their simple explanation. GET THE NUMBERED CODES . Example is something like P0130. The auto parts store will do this free!
3. Return here for explanation and what it takes for repairs. We can save you a lot of money.

DEALERS are very expensive and most do not have the equipment to properly diagnose your car, Chrysler has changed their computer language and their new equipment does not work with the older cars like the Crossfire.

 

Make sure your gas cap is on tight , all the way clockwise until it stops.

 

 

We are all confused here because we are not getting enough information.
Were is the car? Has any work been accomplished/completed by the dealers?
Just by looking at the numbers you have a problem with the Relay Control Module (RCM). It is an easy and inexpensive repair. Use the search box at the right top of the screen and type in RCM repair. lots of information. Most everyone here has removed the RCM from their cars, sent it to tighed1 who repairs it in a couple days returns it to you. CLICK :RCM repair

 

I doubt that most have had the RCM fixed by tighed1, anyone capable of soldering can do the job. However replacing a burnt relay takes the job to another level. Most of us have a spare which we carry in the trunk.

 

No work has been done they said they couldn't do it at that dealership I am driving the car it is not having any issues engine light is off now but was told this is what triggered light. I am going to take it on a 3 hour trip and am concerned if light comes back on car will quit running

 

Looking at where Forrest City is...here is a trusted independent Mercedes repair shop. They can repair your crossfire.

Home | South End BMW Auto Repair, Mercedes Auto Repair and Audi Auto Repair
Also here is a link to the part your car should need to repair it.

https://www.autohausaz.com/pn/MB-1705450105

Also the Yelp page.

https://www.yelp.com/biz/mp-motorwer...ercedes+Repair

 

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You are in the right place. Since the car is running you are not that bad in the fact it is running. Is there a member near that can help with repairing/replacing the RCM?


Look here, this member is north of Spartenburg SC in NC ( https://www.google.com/maps/place/Fo...!4d-81.8651028 ). There are a few members in northwest SC, am not sure one is near this member. That shop ( Home | Charlotte BMW Auto Repair, Mercedes Auto Repair and Audi Auto Repair ) is located in Charlotte NC, many miles due east of her.

Hope you find someone to help or find an independent MB shop closer to you if you can't do any work yourself or get a member close to you assist any. Good luck!


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You are correct 180; To rephrase my sentence then let me say that many have sent their RCM to tighed1 for repair.

Oscar455$, one of the jobs of the RCM is to feed electricity to the air pump at the very front of the engine. That pump runs for a short time when you start your car. In the center of the pump there is a ground connection that has been know to cause intermittent trouble. It is a single bolt with several wires. Unscrew that bolt, clean it well and the area where it seats, then reconnect. Just maybe, it could be causing your problem. The code P0410 in the picture you sent leads me to believe your problem is with the RCM as it relates to the air pump. The oxygen sensors and the air pump are all related as part of the emission controls. Also as has been previously stated be sure to turn the fuel cap all the way tightly closed after putting gas in the tank.

Driving the car with the air pump not functioning properly is not a problem, but if the oxygen sensors are not working properly that will cause damage in the long term.
If your problem is in the RCM it could develop that you will not be able to start the car; There is no damaged caused, but you will be stranded until the RCM is repaired.

Hope that answers your questions and you find it helpful. Good luck.

 

All valid points! I also believe/suggest the air pump not working might also trigger some O-2 codes (pending or not) since the air pump (like the O-2 sensors) work with some of the emissions circuits. I would first start with the RCM (relay control Module). It IS a simple swap, many how-to's here in the forum. I say again, if it is driving it is not as bad as some (if not all) mechanics would lead you to believe. The RCM is not a high priced part and MAY SAVE you a LOT of $.


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