Cupcar

My airbag warning lamp is on as well as the central informer !

I know about using resistors in the circuit to fool the airbag controller that there is an airbag when there isn't.

My problem is that I have removed the entire system - both airbags and the controller module.

I was surprised the airbag lamp is still on as well as the central informer lamp (still defeatable). Looking at the wiring diagram the signal goes from the airbag controller to the lamp in the clock and from there on to the central informer. I assumed the lamp would not be an issue with the controller not in the circuit, but it appears the central informer needs a signal.

Any ideas here?

Turbodan

circuits in the clock are damaged...happens all the time on these old cars. try the search function you will see it discussed often. Send it to Palo Alto or North Hollywood Speedometer to have all of the circuits resoldered. there is a diy that shows you how to test it with a voltmeter.

Cupcar

It looks after more careful review of the wiring diagram that the central informer wants 12 volts at pin 16 to keep it above ground (same as pin 7 on airbag controller) which would also turn off the lamp in the clock.

I will test this tomorrow.

Cupcar

Thanks, I will check board for bad joints as well.

jscott82

How did you handle passing power to the ECU when you removed the controller?

I read in another post recently that the wiring harness plug has shorting jumpers in it. You either need to create a jumper plug to mate with the wiring harness or defeat the jumpers in the harness plug.

Hard to describe, hope it made sense..

For mine I made a jumper plug to plug into the wiring harness. Everything works fine, no warning light.

https://rennlist.com/forums/showthre...ferrerid=45114

Cupcar

Of the "Airbag Control Unit" plug, I ran the Pin 5 "Term. 15" (=+12 V. from ignition switch) across a kill switch to Pin 20 "MFI Term. 15" (Terminal 15 of fuel injection) and this works, switch kills FI and engine.

I note that the Airbag Controller Unit's Pin 7 "Warning Lamp Airbag" wire goes to the ground side of the clock's warning lamp and then on to the "Central Informer" unit at its input to Pin 16 (of white plug 2) .

My bet is that +12 V normally comes off Pin 7 of Airbag Control Unit to Pin 16 of the Central Informer and if this voltage is turned off by the Airbag Control Unit the Central Informer unit then grounds the clock lamp (normally this lamp has +12 V. on both sides of it and is off) and also turns the Central Warning Lamp to "on" which is a separate circuit.

Cupcar

Thanks a lot the last post in the string you site by Aussie Alan I think is the key to the solution, the text of which is:

"So this old thread helped me understand how the airbag module interacts with the DME in case of an accident that deploys the airbags but there is something I can add about the light.
My car is a 95 and I had to remove my faulty airbag module for a science experiment and the engine would't start, after reading this thread I made a simple jumper and put it into the connector plug across pins 5 & 20, BINGO, car starts but airbag light is still on.
After reading the manual, I figured that the plug has short circuit bridges between certain pins which only work when it's unplugged, the one between pins 6 & 7 controls the light, so I grabbed a plastic zip tie and pushed the end into the slot adjacent to pins 6 & 7 and SUCCESS! no light.
Also worth noting is the pins for the airbags are automatically shorted to prevent any possibility of accidental airbag triggering from static charges.
Hope this helps someone else like it helped me.

Cheers
Alan"

Aussie Alan 993

Glad that was helpful to someone, my module is out to be reprogrammed by a guy who says he can bring a dead module back to life if it is not physically or electrically damaged or full of water, even if it can't be reset with a scanner.

Fingers crossed.....

Cupcar

Just to finish off this thread here are pictures of the "final solution" using the tip of a tie wrap cut off and inserted into airbag connector.

s14kev

Resurrecting an old thread. I just removed passenger and driver airbags. Did the 2.7 ohm resistor trick for both airbag plugs but airbag light and central warning light is still on despite resetting with the Durametric. Not sure of the reason for this. Since both airbags are gone, I figure the airbag controller is not needed. It sounds like 3 steps are needed to get this to work

1. Unplug orange connector from airbag controller
2. Jumper pins 5 and 20 on the harness side of the orange airbag connector to provide power to the ECU.
3. Insert cable tie end into slot next to pins 6 and 7 to turn off warning light

Changes needed to connector are outlined in a photo stolen from Ponchobroke in the thread shown here:
https://rennlist.com/forums/993-foru...r-removal.html




It looks like Cupcar did not need to jumper pins 5 and 20? Am I missing something?

Cupcar

I bridged them otherwise no fuel pump operation. This makes sense to turn off fuel pump after a crash.

s14kev

Ah ha. That makes sense. Safety first! Unless of course you are irresponsibly removing airbags in a small car with over 500hp and the front driveshaft/diff removed....

Cupcar, did you bridge them at the connector or somewhere else in the harness?

I don't know why people would bother with the whole airbag resistor deal. This seems so much simpler and does not require cutting of the harness or sourcing spare plugs from a clockspring and passenger airbag to splice in a resistor without cutting the factory harness.

Cupcar

I separated the wires out extended them to the kill switch to shut off pump. Frankly, I think airbags can be a liability if using a 6-point harness on the street and are used to a car being out of control - particularly in a multiple impact situation.