DansSlk

Hi i have not long received my second SLK55 and have had the MIL come on now i know what the problem is and have rectified it but i noticed that the freeze frame data stored in the car is all wrong to give a few examples the rpm reads 81124 the coolant temp 2,000,000 degrees and the air flow rate reads 0 and i am unable to clear these values using my ElmScan unit and various different computer programs the code cleared OK but thats it, i have also tried my mates hand-held scanner on the car but again had no effect.
The car runs fine and goes like a bat outta hell but there must be something not quite right with it and i am a little bit worried about it after having major electrical problems on the first car any help you can provide will be much appreciated.

Thanks
Dan

Vic_E55_2001

You need OBD scanner with CAN BUS, like auterraweb.com...
or take it to the dealer...

DansSlk

Hi both the scanners i have used on the car support CAN BUS and i can clear fault codes and read live sensor data fine its just the freeze frame data that i am having the problems with but my SDS machine should be here soon so i shall try that on it also if that don't work nothing will any other ideas will be very much appreciated.

Dan

MBTech21

Mostly this comes from the logic built into the ECU, to simplify it, think of it having 2 halves of it's brain- the MB side- which only talks to the SDS and has all the info that it can hold and give out...and the OBD 2 side, which stores the bare minimum it is required to by law and thats it. OBD 2 scanners only talk to the OBD 2 side, which isn't very smart, if the scan tool is expecting a value and sees nothing, it substitutes (much like the ECU does).
I'm a little confused by your post though- you said this was the freeze frame data and you could clear the code, but not the freeze frame data? How are you reaccessing the freeze frame for a code that is no longer there? Or are these the 'actual values' on the car? which don't usually show up on the OBD 2 side of the brain.

DansSlk

Hi thanks for the reply i cleared the code after reading it and did not think to check the freeze frame so just out of curiosity i check the freeze frame values with the PC expecting nothing and got all these funky readings.

The 'actual values' as you put it are also accessible to me and they are being displayed just fine no probs at all i can also access things like the climate control and the comand i have no idea when these freeze data was stored and there are no codes in any of the modules that i can access as far as the car is concerned things are just dandy so it is just these values that are wrong on my SL using the same piece of kit there are no values in the freeze frame section so it is the car sending them to the PC i just don't know why.

Any ideas will be greatly appreciated

Cheers
Dan

MBTech21

My guess would be that its a glitch with OBD2 software in the ME unit, which is really of no issue anyway. If you could see it with an SDS machine, then I'd be thinking that a problem was there, but its really probably a software thing.

DansSlk

Hiya thanks for the reply i will get my mate to plug his SDS into it and see what it comes up with and will report back. If its just software would that explain the increased access to the systems in the car as i thought that different devices where connected to different pins in the obd socket but at the same time i know there are networks so i am just curious about how it works.

If the star also has the problem do you think its worth a dealer visit as i said the car runs fine so its just this one problem

Thank you very much for your help

Dan

DansSlk

OK as promised i had mark plug in his SDS and it has the same problem all this freeze frame data was still there and the machine could not clear it because there where no fault codes also the machine could not communicate with most of the modules on the car but when i used my software i accessed them fine he said that he has never experienced anything like this on the cars he has tested before.

Any ideas?

Cheers
Dan

MBTech21

Without knowing the version of DAS he is running, that is a tough diagnosis!! We get at least one new piece of software a week to fix some problem or another.
One question, though, how is he accessing thiis 'freeze frame' data?? I don't see how you even have a menu path to it without a code- I tryed today on the simulator, using your car- and I couldn't find anything that led to freeze frame without a code.

DansSlk

I will find out the version that he is using if it helps he got the machine about 3 months ago so from what you have said that makes it very out of date what concerns me more is the fact that it could not talk to every module in the car my tester seems fine could that be a prob with his machine and not with the car? i might try pulling the battery for an hour or two or causing the MIL to come on and see if that over-writes whats on it on my machine i have a freeze frame tab that i pick and then it loads it up and then a seperate page for codes so thats how i have been able to access the data.
I will hopefully speak to him tommorow so will ask and i will have a play with the car myself also.
If its just this one bit of funny data do you think its safe to ignore it? sorry to ask so many questions its just that my first slk whas replaced due to major electrical probs so now i am very afraid so anything electrical going wrong.

Thanks for you help

Dan

MBTech21

I would think that if every thing is working ok, then you would be safe to ignore it, The lack of communication with everything suggests its his machine. Some versions of DAS will not talk to certain cars, that why at the dealers, we keep all our machines staggered with the various software levels.

DansSlk

Ok thank you i asked how he found the freeze frame data and he said the machine gave him the same code that i erased thats how he found it but it would not delete caused errors also a bit of good news his machine is playing up so my car is fine, he will get the DAS version for me and i will go ahead and cause another code see if it erases the weird stuff and will report back.

I just want to say thanks again you have been a tremendious help to me its great to be able to speak to a tech, around my neck of the woods that would never happen they are all kept locked away and we are left talking to SA's who dont really know what they are on about!

Cheers Dan


Ok i just caused a few fault codes on the car and have the freeze frame was updated with correct info untill i erased them now its back to the weird stuff so it looks like you said just some iffy software does that still sound right to you?

MBTech21

Sure sounds like it...glad to help

DansSlk

Thank you very much you really have put my mind at ease

Thanks again!