Hi everyone! So I have a w212, whose steering buttons I have replaced. How after a full day of work, and putting it all back, the computer is through in a "front right malfunction consult workshop" and is turning on a red light which is of the air bag if I'm not wrong. Obviously I did disconnect the air bag connection, to do the work. Now is there any known way to fix this issue without going to the shop? There were no issues before doing the button replacement.

 

Nothing like fixing it until it's broken...

What codes are thrown?
Might be as easy as disconnecting the batteries for a bit.

 

If you disconnected the airbag with the battery NOT disconnected... now you have a SRS warning. It requires reset with a scan tool.

 

no code is given, just this message and the srs light is thrown.

 

so what if I disconnect the battery right now, take all apart again and put it back? Also I do have an OBDII 2 Bluetooth scanner, do you know some trusty scan tool for mobile?

Thanks

 

You can try disconnecting the battery for 10 minutes... no reason to install the old parts. In my experience you need a scan tool to reset the code.

 

I'll disconnected the battery tomorrow, also I've gotten to know there are 2 batteries in a w212? One regular the other in the dash? Is that factually correct or nah, and disconnecting the main main under the hood should be enough? I am trying to find a scan tool app that actual works, so far nothing.

 

Yes, there two batteries. Their location and function depends on year/model of the W212. The main (starting) battery is either in the engine compartment or trunk. The auxiliary battery is in the dash or trunk. You would disconnect the main battery if you so desire.

 

Thank you so much, if iam able to find a fix I'll share it here.

 

I don't think the usual ELM327 Bluetooth ODBC-II dongles have the hardware required to talk to Mercedes 4-6 different CANbuses, nor do I think anyone makes any mobile app for these cars. I have one of those dongles I've used with a Toyota and a Ford truck, with the Ford the tool Forscan Lite can read ALL the codes and reset them, but there's no equivalent for Mercedes.

 

the SAM (power module) disconnects the aux battery when the car is off. its only used to power the auxilliary stuff like stereo, navi, lighting when the car is being started, and its connected to the main battery+alternator when it needs charging.

so, no, you don't need to disconnect the aux battery when working on the main electrics or to attempt a power reset of any CU's

 

I have had luck using my Launch X431 V Pro to talk to the CAN buses. I just haven't tried to do any SCN coding of parts. Thankfully I haven't had to replace any parts that require SCN coding yet.

 

You won't be able to SCN... only Xentry "online" on for W212s.

 

Hi everyone, thanks for the input, but had a guy over, he brought a professionally scanner, and cleared the code, thanks anyway.