Hello all. I do a lot of amatuer wrenching but not on efi, Chryslers, or imports. Wife's 06 crossfire base 6sp, about 100k, she's owned for a couple years has a couple issues. I had the (i'm going to call it RCM module) repaired for the sudden no crank no start issue after several tows home then it would restart fine later. That was about 2 years ago, we looked at it and an Elec. tech agreed it looked like the usual suspect needed re-soldered for workmanship defects. He repaired and problem solved. Most of the time she has owned it the low fuel light has been erratic coming on frequently but not always somewhere around half a tank of only highest octane fuel available. The light will come on about halfway through 45 mile commute then stay on til the end of the drive and be off the next time she drives it usually. She tries to keep it above 1/2 tank but has run the guage pretty low without running out of gas.She has complained numerous times about what she calls stinky farts. When the engine is relatively cool, before becoming completely up to normal op temp., if she does any spirited driving at all she will notice a rotten egg smell reminds her of cats plugging up, but has never noticed it after car is up to normal temps. About a month ago it through a ck eng code (forget exact number), but came back as evap emissions large leak. We checked fuel cap and for vacuum leaks finding nothing. A' couple weeks later it came on again and she reset it herself using her own autozone code reader. She will notice vehicle issues that would sail right over a lot of peoples heads. The car seems to run great all the time and she loves it but I'm trying to get out in front of an issue that seems to be cropping up. You folks were amazing on diagnosing the (RCM) repair, hoping this rings a bell and someone can point me in the right direction. Repairs shops, Chrysler and Mercedes shops in N Dallas area have been of no help since owning this car and mostly don't even want to look at it. Might as well just give them whatever is in your wallet and take car back home. Ringing any bells here?

 

I would suspect the fuek level sensor, the wiring/connectors from it to the instrument cluster, or the cluster.
There are only 2 wires involved :

 

Having trouble finding any decent wiring diagrams here, are these same two wires the only ones that operate the guage? Any referral to a good source for accurate schematics? The "idiot" gauge shows half a tank(approx.) when the low fuel light comes on. I was assuming the gauge was the style that responded gradually in order to not bounce around as fuel sloshed in the tank and that maybe the sending unit was bouncing inside the tank setting a computer trigger for the low fuel light. I just included it in order to give as much detail as possible on issues we are starting to see. And all these ideas spawn from my experience with NON-Chrysler, NON Mercedes, NON efi systems. Thanks for any and all input.

 

You might google "Mercedes Low Fuel Light". That light can come on to indicate issues with the Evaporative system, but it was my understanding that in such cases, it FLASHES.

It would also be helpful (maybe) to know what code was set that she reset.

I have a problem with the light coming on with the gauge up so high, the same sensor drives the gauge and "low fuel light" operation, in cases where it is indicating low fuel level. It is certainly not indicating low fuel level in this case, not the way you describe it, anyway.

And there are no complete wiring diagrams for these cars - all you get is what is in the service manual, it is both incomplete and less than 100% accurate.

 

Take a look down at my sig. Within that link are several service manuals, I generally use the 2005 SRT6 one.

 

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Just a thought, given your OP, you said " About a month ago it through a ck eng code (forget exact number), but came back as evap emissions large leak. ", and pizzaguys note about the flashing low fuel light, you MIGHT have an answer your asking for as to the cause. Troubleshooting that evap system is beyond my ability as I know nothing about it per say. Might start looking in the service manual, at that specific system. You didn't mention the low fuel light flashing (like PG said in his post #4) so maybe you can confirm? Good luck!

 

very good info, I've never seen it but I think she does describe it as flashing, I'll have to confirm with her later. I'm also looking for more on the service manual referenced by ala_xfire. I think we have an owners manual and a Haynes, which means if we are lucky we can find which fuse to check on this bloody mercedes crossbreed. Thanks again and I welcome the feedback. She really likes that car and she is very supportive of all of my interests so I will learn and do all I can to help keep this Chrysler project up and running.

 

You have two issues, emission and fuel.
The fuel light may come on when there is a poor connection causing resistance variables but most probably a faulty sensor in the tank. The Service Manual explains the procedure to check the sensor. Hardly anyone checks out the component test procedures explained in the Service Manual.
The emission problem could be a leak in a cracked hose or a loose fit on a nipple, if you have a catch can you should look at the hoses and connections on it. Leaks in the valve covers could be causing problems as well.

 

while looking for the service manuals referred to by ala-xfire i found the link to related topics. several/blinking flashing fuel light threads there I didn't find when I searched earlier. I'm betting that she, like me, tends to restart the fuel pump several times trying to get the tank full. We tend to do a lot of daily driving 90-200 miles a day so we try to get the tank & full save a couple fuel stops a year. At the end of life I want that time back spent on such things as fueling and waiting at the traffic light when there is no other traffic. I have a couple good leads now on this issue, if any one has more to share please feel free

 

No wonder that light is blinking. Repeated flooding of the evap canister will cost you a week's pay.
Several here have been thru that. There is good reason the manual tells you "do not top off tank".

And this applies to more than just the Crossfire, altho I can certainly attest, after being here eleven years, our cars seem to be more unforgiving about this than many other products.

 

There is an air space above the gas when the tank is full, this is where the fumes are sucked away from at times controlled by the solenoids located by the brake master cylinder and there is a valve in the tank to prevent over filling. Look at the fuel tank diagram in the emissions section of the Service Manual.
The gas tank runs with a slight vacuum from the engine vacuum system.
You can overfill the tank and fill the charcoal filter if the valve at the bottom of the fill tube is jammed open.

 

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I second, third, fourth, and forever, advise never to continue to 'top off' a fuel tank by consistently sending fuel into a full tank. This will cause a number of potential problems including those mentioned here. These cars are not the cars of old. Best advice, and I hope you haven't caused irreversible problems to date. Good luck!



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