SRS Airbag Fault
Hello,
I am trying to sort out a problem with the airbag / SRS light being on.
It happened after trying to start the car with a low battery.
Anyway, I figured it would be a simple issue to reset it. It's a 1996, G300e, and the is a 16-pin diagnostic connector located near the brake-servo in the engine bay. Only pins 1 (Gnd) , 6 (SRS) and 16 (12 v) are populated in the socket.
I tried to use a carsoft clone, with analogue connector to reset the SRS, but it cannot find the airbag control module. I then wired-up an LED with 330ohm series resistor (for 30mA) and parallel switch to try to do a manual diagnosis of the flash-codes, however, the output on pin 6, has hardly enough power to light the LED, although it does indicate 12v with a digital multimeter.
So, I figure that I will need some help with this such as a wiring diagram with relevant components, relays and fuses, and also, where is the SRS control unit located?
Thank you
Have a word with Roly he may be able to help you out .
You will probably need to get a dealer to reset the light for you. I don't know how you can reset it without a proper tool, HHT or the PC DAS system. I used to have a Carsoft laptop and it used to reset the AB module ok on a 38 pin plug.
Reading the code won't tell you much, only that there is a fault, which you already know. If you disconnect the AB from the system it activates the light. It probably registered a low voltage when you were trying to start it an triggered the fault.
I have a diagram which shows the AB control module near the gear level under the low centre console and, obviously, the AB itself is behind the steering wheel. Does your horn still work?
This is the best I could find. I presume that you have the driver's AB only. Not the later type with passenger and belt tensioners?
Send me a PM with an email address and I'll send you a 2Mb file with all the instructions for the ab retrofit, which has lots of tech info on electrics. Or put it here if you're not worried.
Wow , going in deep.
Email sent.
Hi Arnie,
Re the fault with the SRS in your G300 back in 2004!
The SRS light is staying on constant in my 1994 G300GEL and I was wondering if you needed to change the sensor or just do a reset to clear the fault?
I noticed online the Airbag can be tested using a multimeter maybe this is where I should start?
Any suggestions would be much appreciated.
Martin
Just noticed the fault was in 2015.
Thank you for the replies. The airbag system is on a 16-pin diagnostic connector, which indicates that it is what's called an "analogue" system. Shorting pin 1( Gnd) to pin 6 should clear the fault, but it doesn't. Additionally, there should be a fault code read-out , as flash-oodles when a light or LED is connected between pins 1 and 6 (eg 3-flashes = steering slip ring fault etc) , but it's a constant 12v - no flashes at all.. and the output on pin 6 is too low to drive an LED, which may indicate some fault with the module.
The steering wheel horn is fine, and I have moved the steering wheel back and forth in case the brushes were sticky.
I therefore think that somehow the airbag module has failed completely, and I am thinking I will need to replace it. However, first, I need to find where it's located, but I don't know whether there are two modules ( main controller and crash sensor) or just one integrated module. I believe that the crash sensor should be somewhere on the transmission tunnel.
Do you have the wiring diagrams, please? id like to check whether there may be any relevant fuses or relays to check as well.
i see that Mercedes w124 airbag modules sell for about £10 on eBay, but I need to see which is the correct one.
Thanks