Recurring airbag light- solved

[bigwinn]

Still looking like low resistance on that right airbag according to those codes, since the wiring is intact and clean connections next step would be to switch out the airbag for a known working one, scrap yard should come up with a suitable replacement with same part number as yours.replacement is fitted and then the code cleared see if the code returns. If it returns then delve into the airbag module connection and check the plug and pins for cleanliness that end. Use a voltmeter set to 200ohms and put the leads on the wires that come from the right airbag and see what resistance number you get that end. I do know the pretensioners must have less than 1.0 ohm recent test on a pair of those I made showed up as 0.4 and 0.5 which was in spec, not sure what you should have on an actual airbag at the moment.
Just found this thread which may be of interest https://www.m3post.com/forums/showthread.php?t=1498270
Seems their problem was broken tabs in the airbag plug causing low resitance, double check yours for damage.
They mention 2 x 2.7Ohm resistors were put in place of the airbag and that took the warning light off so their airbag needed that resistance to satisfy the main module. I invested in a small resistance diagnostic test meter a few week back but not used it in anger yet. It can be connected to the wiring and a range of resistance adjusted until the right setting turns the light off on the dash with an ignition cycle. Using this would at least prove the wiring is ok and the actual airbag is at fault which a normal volt meter can't tell you.
https://www.ebay.co.uk/itm/223475405476

Reading your edit- a temporary fix is to bridge the socket with resistors?

Don’t get me wrong I’d prefer it working but to get the light gone that’s an option?

The tabs are ok I checked them

 

[bigwinn]

Still looking like low resistance on that right airbag according to those codes, since the wiring is intact and clean connections next step would be to switch out the airbag for a known working one, scrap yard should come up with a suitable replacement with same part number as yours.replacement is fitted and then the code cleared see if the code returns. If it returns then delve into the airbag module connection and check the plug and pins for cleanliness that end. Use a voltmeter set to 200ohms and put the leads on the wires that come from the right airbag and see what resistance number you get that end. I do know the pretensioners must have less than 1.0 ohm recent test on a pair of those I made showed up as 0.4 and 0.5 which was in spec, not sure what you should have on an actual airbag at the moment.
Just found this thread which may be of interest https://www.m3post.com/forums/showthread.php?t=1498270
Seems their problem was broken tabs in the airbag plug causing low resitance, double check yours for damage.
They mention 2 x 2.7Ohm resistors were put in place of the airbag and that took the warning light off so their airbag needed that resistance to satisfy the main module. I invested in a small resistance diagnostic test meter a few week back but not used it in anger yet. It can be connected to the wiring and a range of resistance adjusted until the right setting turns the light off on the dash with an ignition cycle. Using this would at least prove the wiring is ok and the actual airbag is at fault which a normal volt meter can't tell you.
https://www.ebay.co.uk/itm/223475405476

Reading your edit- a temporary fix is to bridge the socket with resistors?

Don’t get me wrong I’d prefer it working but to get the light gone that’s an option?

The tabs are ok I checked them

Re reading the linked post- maybe further investigation is needed into the tabs…

 

[colb]

Yes bridging with resistors would be a temporary soloution to the light, the airbag wouldn't be functional if you do that.

 

[bigwinn]

I’ll swap the bag see what happens

 

[bigwinn]

On we go

Swapped airbags over and the airbag isn’t at fault

Going to pop a resistor over the plug to see if that makes a difference

 

[enuff_zed]

Stuart, every time I open this thread I'm expecting to see your face covered in blood and talc!

 

[bigwinn]

I always play safe

 

[bigwinn]

Yes bridging with resistors would be a temporary soloution to the light, the airbag wouldn't be functional if you do that.

Gentlemen I think we have our first signpost to where we are going wrong

I used the resistor device you pointed to Colb- very good!

Bridging the terminals of the door airbag to see if I could deduce the resistance- first run I got TWO errors on INPA

The existing fault and the new thorax airbag fault

So after all this time have I been chasing the wrong airbag???

I have had the steering wheel off for recovering- could that be the airbag at fault?

See screenshot

 

[colb]

First mention that you have had the steering wheel in bits to recover it, seem that with a resistor in the side bag connection it threw a new code for that. May well be we have been looking at the wrong airbag, since you disturbed the steering wheel bag thats the next place to look and check the wiring and resistance. Put the side one back in and leave the resistor out of that try it in the steering wheel bag connection, clear the codes and then cycle the ignition to see if the code comes back.
Translation of Seitenairbag is Side Airbag which is confusing.

 

[bigwinn]

First mention that you have had the steering wheel in bits to recover it, seem that with a resistor in the side bag connection it threw a new code for that. May well be we have been looking at the wrong airbag, since you disturbed the steering wheel bag thats the next place to look and check the wiring and resistance. Put the side one back in and leave the resistor out of that try it in the steering wheel bag connection, clear the codes and then cycle the ignition to see if the code comes back.
Translation of Seitenairbag is Side Airbag which is confusing.

First job in the am Colb

Will let you know how it goes

 

[bigwinn]

I’ll just leave this here.

Connector in steering wheel airbag not secured

I need to learn German

Colb you’ve been steadfast in supporting thank you!

Stuart

 

[enuff_zed]

Well done mate.
Perseverance, with lots of forum help and happy to own up so we all learn from it.

Better check that coolant sensor connection again then.

 

[bigwinn]

 

[colb]

Well I never, who would have thought about looking there? Have a smattering of German understanding so immediately took the description to point to the side airbag not the steering wheel one. If you had let on you had the wheel off at the beginning we might have gone there first time. At least we all have some better understanding of the system now, Nice feeling when that airbag light is extinguished, mate who had his Z3 airbag light on and couldn't be cleared was overjoyed when I found out he had the wrong replacement module fitted to his car, replaced it with a correct one and coded it to the car and extingished the light within a few keystrokes on the laptop using NCS Expert. Made a change from the usual under seat connections being the cause with yours.

 

[bigwinn]

In other news the level warning for coolant was sorted too

To do list down to 3 items!

 

[enuff_zed]

In other news the level warning for coolant was sorted too

How?
Butterfingers on the connection?

 

[bigwinn]

In other news the level warning for coolant was sorted too

How?
Butterfingers on the connection?

Gentle and not so gentle big hammer action

The float must have been stuck

 

[enuff_zed]

In other news the level warning for coolant was sorted too

How?
Butterfingers on the connection?

Gentle and not so gentle big hammer action

The float must have been stuck

Ah ha! So a tip to all members fitting a new expansion tank.
Give it a good shake first to make sure the lower float is moving ok.

If nothing else, at least everyone must now have a better understanding of the overly complicated workings of the expansion tank.

 

[bigwinn]

How?
Butterfingers on the connection?

Gentle and not so gentle big hammer action

The float must have been stuck

Ah ha! So a tip to all members fitting a new expansion tank.
Give it a good shake first to make sure the lower float is moving ok.

If nothing else, at least everyone must now have a better understanding of the overly complicated workings of the expansion tank.

I forgot to cut the old one up and it went to the landfill... sorry must try harder next time

I'm sure I'll have one to cut up soon...