March '07 build of JustaCooper R56 with a passenger seat weight sensor failure causing a red airbag warning and a seatbelt warning on speedometer plus a Pass Air Bag Off warning above the interior rearview mirror - per dealer's diagnosis. Repair cost $1100. yuk!

Here's the question: If I disable OC3_1 and OC3_2 in the ABG module, will the air bags still deploy? (It's OK if they will always deploy, as only adults use the car.)

If you know the answer, please share. I really want to thank the contributors to the NCSExpert post(s). Having the ability to fix silly errors and tweak preferences renews my interest the Mini.

Dave

 

It might help some forum members to see what the weight sensor looks like. Here are a few pictures.

The first picture shows what the sensor looks like (removed from the fabric) sitting on the seat -- a flexible circuit board, with little button-shaped sensors all over the place.


The second picture shows the top of the circuit board. I Ohm-ed out the traces and found one that was suspect measuring between the silver connection and the center power pin (lower-left side of the board). The suspect pin is colored with a black Sharpee.


The third photo below shows the underside of the board. Note the conformal coating is peeled away on these last two pictures to better view the board and components.


I read a post somewhere saying that one could not substitute a 2.2 Ohm resistor for a weight sensor on these 2nd gen, R56, designs. Based on a preliminary exam of that double-sided circuit board with active components, I'd have to agree.

 

Thanks for the excellent pics and investigation. I believe that the output from the circuit board is digital, which certainly could not be replaced by a resistor. However, if a physical failure can be identified, there might be some possibility to repair or bypass it. You found a trace that was suspect. I wonder if something could be applied to that one trace (such as a resistor) that would clear the error. My thought is that the mat is made of many individual sensors, and a fault in just one of them may cause the entire mat to be registered as failed.

 

After looking at these pictures I cant quite tell if the circles are small circuit boards or not. If they are not and are just on/off pressure switches we should be able to beat this thing. If it is just on off switch. Then the circuit board should put out an on/off signal through the board. Then it will either receive/ or not receive the pulse back. So all we would have to do is find out where the pulse originated and where it should be received. Then soldier wires completing the loop.

 

I think they are ON/OFF switches. The idea is that "weightier" persons will activate all of them, while smaller/childs activate only a portion, those in the middle.

 

So my theory might work

 

Could you find a donor seat from a junkyard?

 

Excellent pictures!! I've had isolated trouble with the occupancy mat.

With the "Pass airbag off" light on, I would not count on the bag deploying. But if you enable the bypass in the ABG module with NCS, I bet the airbag would work. In the R56AT.000 file, the VO code that disables the occupancy mat seems to be EOC3.

Try coding the VO retrofit, and see if the pass airbag light stays out. If it is out, I would feel confident the bag will deploy (if anyone is there or not, like mid-90s cars).

Compare the ABG module before and after "defaulting" with the new VO to see if/what was changed.

If that did nothing, then I would try modifying the ABG trace file directly.

Good luck!

 

In my 2008 R56 in the ABG module, I only have GK_OC3_POL and OC3. Should I deactivate these two?

I am trying to get the lights to turn off, but have the airbag work in case there is a collision. Would the airbag deploy if the passenger seat belt is not fastned?

 

I am attempting to disable the light and seat sensor on my '08 Cooper S as well. Did you get a response to this post?