SRS warning light wont go off!!!

[pbforce]

I have a problem with the SRS warning light. Is ON all the time
Its an E220 93 mod.

I have tried three different airbag relays,CPU (placed under the ashtray).
This is becouse my local MB dealer found out with an blinkcode tester that it was errorcode 10, defect airbag control unit. Is this right?

The last relay I tested looked OK when I switched on the ignition for the first and second time, the light was turning off after about 5 sek.

But now it is only ON again

Does anyone have an idea of what it could be? Could it be somthing else that makes this error?

Please help an desperate Norwegian!!!

 

[CarstenG]

I had same problem with my E220 CDI (2000 model). It has a sensor/switch in the front passengers seat that disables the airbag if a child seat is mounted. If the sensor/switch is broken the SRS warning light stays ON. I don't know if this is valid for a 93 model.

 

[piestore]

srs

Hi

your car doesn't have passenger seat recognition so don' look for it. You need to get the current fault code to stand any chance of tracing it. One common fault was the plug underneath the front edge of the seat which goes to the seat belt buckle (both sides) the wires used to break and the solder joints would create a high resistance cut the plug out and solder the wires together as they were when te plug was there, even then you need to get the fault erased with the blink code tester

good luck

 

[mashbury]

A problem shared is a problem halved (!?)

I have exactly the same problem. I have a 92/93 300TD W124. My existing SRS ECU has a fault, I have now replaced this twice, each time the replacement unit gave a fault code of 10. As you say, this indicates that the unit has been activated, i.e. has set off the airbag, and is now useless (and the SRS light will be permanently on).

However I do not believe both are faulty. I have since learned that there is a known fault whereby the SRS ECU erroneously gives a fault code of 10 due to it being over-sensitive to earth (ground) potential difference. The remedy seems to be to ensure you have an ECU post 1990 (I think), and " attach the ground cable shoe of airbag harness at lowest point". Trouble is, what exactly does this mean? The statement is pretty cryptic, and without the wiring diagram it's not easy to guess what to do.

So far I haven't had time to play around with the earthing around the SRS unit (as you say it's behind the ashtray) but I'm hoping I will stumble across the solution...if you try this and get there before me please let me know.

Thinking about it, this dodgy earth would be consistent with your observation of it being OK for a few times then failing...

Anyone else been down this road??