CLk55 SRS light (w209)

[Johnmor]

HI All

Recently purchased a CLK55 AMG Cabriolet , done around 1200 miles and had a great time, all seemed well

However the SRS light came on and seemed to stay on for a while and then would reset, however is now permanently on, i suspected the famous passenger seat pad fault, checked all connections are secure, purchased seat pad emulator and is showing connected (led working) but the light wont reset,

• Is it possibly something else, poor resistance etc
• Will light reset itself, seemed to previously when seemed bad connection.

As a side issue the passenger seat belt presents itself even when no passenger in the seat, could this be linked??


I have trawled through many reports regarding SRS light but many seem to be around older vehicles or 208 clk



any help would be beneficial



thanks
john

 

[edspin]

only help I can give is that my airbag light is off and with no passenger my passenger belt butler deploys assume you checked both front seats

 

[Johnmor]

Thanks for that
I thought maybe the seat pad also activated the seat belt butler, just to complicate things but it seems it may not be related, I hvae checked both seats however the driver seat doesent seem to have the same connections , i assume if the car is being driven then there must be someone in the seat!

Thanks

 

[sjmaxwell]

The SRS light has to be reset with the appropriate tool I'm afraid, it wont do it automatically.

I don't usually recommend the emulator as the air bag is a safety feature and by putting the emulator in, the car is being conned into thinking there is a passenger therefore in an accident it could go off unnecessarily - just don't put anything on the seat like a baby basket because it will become a projectile!

This is possibly the reason the seat belt is being offered although I think it works on the opening of the passenger door. All I can suggest is that try removing the emulator and see if the belt still gets presented or it reverts to depending on the passenger door being opened.

 

[markjay]

You need to get it on STAR.

I have an Autel MaxiDiag that can read and reset MB's SRS fault codes, but proper STAR is better.

 

[sjmaxwell]

You need to get it on STAR.

I have an Autel MaxiDiag that can read and reset MB's SRS fault codes, but proper STAR is better.

Not sure why STAR is better to reset the SRS but as you say some Autel tools will do it which is why I said appropriate tool!

 

[Johnmor]

HI

Yes , I realize that the emulator fools the system and is not ideal, but it will indicate if it is definitely the seat pad should the system reset. I can then sourse a replacement pad

I have an early version of the Autel reader but it wont do SRS, Markjay what version of Autel Maxidiag do you have, my mate has a MD801 and I'm hoping it will diagnose SRS faults and reset the system

thanks all

john

 

[sjmaxwell]

HI Yes , I realize that the emulator fools the system and is not ideal, but it will indicate if it is definitely the seat pad should the system reset. I can then sourse a replacement pad I have an early version of the Autel reader but it wont do SRS, Markjay what version of Autel Maxidiag do you have, my mate has a MD801 and I'm hoping it will diagnose SRS faults and reset the system thanks all john

I have an 804 which does

 

[markjay]

Not sure why STAR is better to reset the SRS but as you say some Autel tools will do it which is why I said appropriate tool!

STAR is not better to reset the SRS... but STAR is better in reading the codes and pinpointing the issue.

 

[markjay]

The one I have is a previous model Autel MaxiDiag EU702 which can read MB cars up to 2006-2008.

The latest models are either Autel MaxiDiag Elite MD702 or MD802:

http://www.autel.com/autelcms/Professional Scan Tools/390.jhtml

http://www.autel.com/autelcms/Professional Scan Tools/393.jhtml

 

[Johnmor]

Thanks for the info,

I bought i980 icarsoft code reader, nice little piece of kit and seems to read and identify the faults so I can reset and access code when needed.

I have got the fault readings and it appears i have:

Fault -open circuit on B48 (occupancy sensor)
and high resistance on 12/1 passenger ignition squib (seat) and cannot reset

I connected the emulator to see if that would remove occupancy sensor issue, led illuminated on emulator but no effect fault still there

starting to suspect bad connections back to SRS ecu somewhere, i removed carpet from passenger footwell and checkd ellectrical connection near the front of sill area (not sure if that is part of the SRS system though) all appear to be in good condition, cleaned large earth connectors in foot well, no change

The srs system appears to use yellow connectors, is this maintained through the wiring loom, IE can i assume connector that are white, ,blue, brown etc are not SRS related?

I feel i will have to remove the seat and follow connections to see if there are further connectors between under seat connection box and loom.

Car will be garaged over the winter and MOT due in June so I have time to fix this, just need a clue as to where to look.


any help appreciated