IanRC

Hi, need help removing DTC B1859 - SRS light. In STAR the DTC is airbag squib (drivers) resistance too high. I did remove the code but after driving for 20 minutes the light came back on. I have checked connection under passenger seat and it's dry and tight. Is there a known reason and fix for this code please? many thanks

seven_out

Star Diagnosis explains how to troubleshoot this problem, and the WIS software explains the repair procedures.

IanRC

Hi Rod, thanks for the info - I have been looking in STAR / WIS and the repair mentions disconnecting N2/7 SRS control module (no idea where this is) and checking resistance is less than 1ohm. Also another post mentioned a possible re-wire of the connectors under the steering wheel airbag? I was hoping for a home repair but sounding more like a dreaded trip to the dealer as I can't fix what I don't know id broken - any more thoughts? cheers, Ian

seven_out

Most SDS kits have an application called "STAR Finder" for locating components. I have attached a screenshot showing the location of N2/7.

IanRC

Hi Rod, thanks for the info - did not realise I had that software - will make life easier. Now to clear some faults and get other issues resolved

timeguardian

2004 SL500

SRS light on, Per my Autel AL619 code reader;


9077 error code
VINs in control module N2/7 (Restraint systems control unit and N73 ( EIS [EzS] control unit) are not identical.


Looks like someone must have changed out the N2/7 module in the past. Does anyone know if this has to go to dealer to be replaced with a new unit and programmed with correct VIN or can the existing unit be reprogrammed?

Any help would be appreciated. Thanks



N73 control unit must be original because I recently purchased a new key from dealership and it matched the VIN of the car.

seven_out

The only way I know of to correct the VIN stored in your vehicle's SRS controller is to use a Star Diagnosis (SDS) computer that has a software "developer key". I believe no dealer will have this, as Mercedes intended it to be used only at the factory.

You can purchase an SDS from alibaba.com or eBay for as little as $300. I have read that most of these systems have the developer key installed. I have read on this or another forum that there are free applications on the internet that will generate a developer key for systems which do not have one installed.

stockton117

have you found an answer to the srs light on the sl? I am having the exact same issue on my friends cl55. I Know no one has changed the srs module because I am the only one who works on the car. Let me know. I will fill you in if I figure it out this......which I will.

timeguardian

I have found out that the most common problem is the child safety seat / passenger airbag off feature which makes the SRS light come on when the SRS command module detects a certain weight upon the passenger seat. There is a resistive panel in the passenger seat which can be damaged if someone kneels on the seat. I have installed a bypass module under the seat and that took care of that problem. I purchased the Carsoft V12 system and had no luck with it. It was "unable to communicate with the SRS command module." I than purchased an Autel AL619 handheld unit. This unit is very nice and easy to use. I received two errors. First was child seat issue which it allowed me to erase. Second, it told me that the VIN number in my SRS command module was different than the VIN of the car. This is my only error that it can't erase. I have to have dealership install a new module and program with correct VIN number. Car is used and was never in accident. Looks like previous owner had someone try to fix the SRS light issue, which was probably caused by the child seat, by exchanging the SRS module. I am going to live with the light for now and have dealership fix if I ever have to bring in for other problem. I do recommend buying the Autel unit. It not only works on my SL500, but it also works on my Ford Explorer. Cost about 140.00 at Amazon and worth it. I only wish MB would not assign VIN numbers to modules. This is not necessary unless they want owners to go to only dealerships for service. Good luck.

stockton117

Thanks for the quick response. I have the autel maxidas DS708 that i use at my shop and it is badass. I also have acces to the latest snap on scan tool which i haven't tried yet but i will on monday. I don't want to burst your bubble but i don't think the srs module is going to fix the problem cause i know for sure my friend has never changed it out. I am starting to lean more towards the EIS module as the culprit from my research but i am not sure yet. Please keep in touch as our info will help each other. My friend is driving down Thursday to pick up his car so i hope i have it figured out by then CHEERS! Sean

stockton117

did you car set with a dead battery for any length of time?