Serial communication link malfunction - Benzworld.org - Mercedes-Benz Discussion Forum

flash18 · 09-07-2009, 03:09 AM

Hi everyone ,I read the benzworld forums regularly and have saved a fortune using the information posted to troubleshoot various problems that pop up with the mercedes i keep collecting .

However i have drawn a blank with a problem with my 2000 a class 160 which has travelled a mere 44000k . It has gone into limp mode with the abs/esp warning light staying on . Fault diagnosed as p0600 serial link communication malfunction .

This is mentioned from time to time in benzworld forums however no one seems to be able to give a clear explanation of what this problem actually is . A few members have said -ecu/maf fried but i am not so sure . I would have thought ecu/maf problems would have bought up p0100 and p0170 fault codes .

Can anybody give me a concise explanation as to the meaning of this fault ???

lofty · 09-07-2009, 09:46 AM

if you search the web for EOBD codes you may well find the answer sorry can't help further.

flash18 · 09-07-2009, 01:17 PM

Quote:

Originally Posted by lofty

if you search the web for EOBD codes you may well find the answer sorry can't help further.

Thanks Lofty ,I have made some progress . I am quite confident that it is something to do with the CAN wiring and the control modules for the ESP and/or ABS . Hopefully I will have time to work on the vehicle this week and I will give updates of progress

lofty · 09-08-2009, 04:33 AM

For all I know you could be Mercedes Top fitter, I understand thy don't have mechanics which is why they always replace with new parts and don't repair the used ones.

But it is advisable to disconnect the battery before touching the wiring , it's also very worth while looking for abrasion on the wiring looms, see my site for details, it's not uncommon to find abrasion down to the bare wires, and that certainly doesn't help.
good luck hope you sort it.

flash18 · 09-08-2009, 01:33 PM

Quote:

Originally Posted by lofty

For all I know you could be Mercedes Top fitter, I understand thy don't have mechanics which is why they always replace with new parts and don't repair the used ones.

But it is advisable to disconnect the battery before touching the wiring , it's also very worth while looking for abrasion on the wiring looms, see my site for details, it's not uncommon to find abrasion down to the bare wires, and that certainly doesn't help.
good luck hope you sort it.

Thanks Lofty ,I started working on it yesterday ,Started by disconnecting the battery and trying to reset -didnt work . Opened the Control module box ,A couple of the modules had ben broken off there brackets which has made me a little suspicous ,somebody has been in there before me. I now need to check the modules, particularly the ESP module is in working order .I will do some research on how to do this . I have had a good look at wiring looms to modules and the wiring looks to be in good order ,I have seen wiring in mercs where the plastic is breaking down and this certainly does not appear to be the case on an initial inspection.

One thing i forgot to mention the other day is that when engaging in drive or reverse the transmission is very harsh and the engagement happens with quite a severe thump ,I am hoping like hell that this is part of the fault P0600 and not something else

flash18 · 09-10-2009, 03:50 AM

Well ,Im not having much luck ,swapped esp/bas module over with a mates one and it made no difference ,next module i need to check is on the esp unit itself ,but looks like a bit of work involved in swapping over with mates and im not too keen on buying one and taking a punt as they are $300plus from a wrecker . Another thing i noticed today when i started the car up was that there was no display of which gear the car was in on the dash . So it wont even show an "F" . Given that the car will rev to the limit in 2nd im starting to wonder if it is the transmission module that is the problem . Anybody have any ideas as to why car is not dispalying which gear the car is in on dash (ie doesnt display-P or R or 1,2,3,4 or D

lofty · 09-10-2009, 04:01 AM

Flash, inrespect of the 'F' display have you read the mail I put on the link on page 59 thast mentions infra-red sensors on the selector module that when cleaned cure the 'F' Display , obviously it won't in all cases but it is worth taling a look.
Bert Rowe's-mercedes-Benz 'A'-class info. Gearbox (Manual) Dumbell replacement, loss of gears , gear box oil replacement.reverse gear and revering light
then link:- Fully auto ACS transmissions

Hope it's of some help.

flash18 · 09-10-2009, 04:30 AM

Thanks Lofty ,yes had a good look at that page . I wonder whether the dirty infrared sensors could result in no dash transmission mode display at all ? any thoughts anybody?

flash18 · 09-11-2009, 02:35 PM

I took apart gear selector and somebody had drowned it in WD40. Obviously someone had been trying to fix a fault in the past but may have done more harm then good. I know WD40 gets rid of moisture but i cant believe that drowning electronics in it can be that good . Anyway have cleaned it off and will get a good solvent electronics spray to finish Job . Hopefully this makes a difference

flash18 · 09-13-2009, 01:08 PM

Put back clean dry electronic circuit board yesterday, Unfortunately it has not made a difference. I have resolved to buy a good diagnostic scanner and will park the car until I have it .