2002 v70-XC SIPS bag resistance too low.

rlrhett · Post by **rlrhett** » 06 Jan 2015, 14:36

I have developed a trouble code with the SRS system. It is telling me that the left front seat airbag's resistance is "too low". If I unplug it I get resistance "too high", of course.

This is an old car, and I do not want to start tearing at the seat to get to this little side airbag. I also can't buy an airbag at most junk yards because for liability reasons they don't sell airbags. The obvious solution is to unplug the airbag and put a resistor across the leads from the SRS system. I know that means I don't have that side airbag, but I am willing to take that risk.

The only problem is I don't know what resistance it is looking for. 1ohm, .1ohm, 10ohm? I can't even guess. Can anyone tell me what resistance it is looking for?

Thanks.

Post by **chrism** » 06 Jan 2015, 15:32

Can you measure the resistance across the RH (passenger) SIP bag?

draser · Post by **draser** » 07 Jan 2015, 17:40

The airbags I've tested, made by Autoliv, have an igniter that measure 2.2 ohms. There's a tolerance of +/- 0.2 ohms so anything between 2 and 2.4 ohms is considered good. Not sure about your airbags but I'd imagine they'd be close. Rather than removing it I'd look at the connectors, and spray some contact cleaner in there.

Post by **precopster** » 07 Jan 2015, 21:20

On the '99 model V70 in which I used a '95 seat I wrangled four 10ohm resistors in parallel to provide about 2.5 ohms overall. The SRS system accepted that.

Beware that connectors collect corrosion and may need a clean 10 years after manufacture. Then just re-assemble and clear codes

draser · Post by **draser** » 08 Jan 2015, 08:00

How's your back Mike, looks like lifting all those trannies caught up with you?

Post by **precopster** » 08 Jan 2015, 15:02

Better thanks. My 8 year old boy weighs 25kg. He likes to run and swing from my neck as well as fall asleep in the back seat of the car and the low lying couch. Guess I'd better start waking him up.

rlrhett · Post by **rlrhett** » 16 Jan 2015, 12:28

precopster wrote:On the '99 model V70 in which I used a '95 seat I wrangled four 10ohm resistors in parallel to provide about 2.5 ohms overall. The SRS system accepted that.

Beware that connectors collect corrosion and may need a clean 10 years after manufacture. Then just re-assemble and clear codes

Thank you. For reasons I can't explain I was unable to get a reading out of either one. Removing the connector gives me a high resistance error, so I know the line is not broken. There must be a short. I will try adding in resistors until the SRS is happy. At least now I have an order of magnitude to work with!

Post by **abscate** » 17 Jan 2015, 11:07

Yeeks!! When you are measuring resistance you are applying a potential on to the circuit, unlike when you measure voltage.

I don't know what triggers an airbag, but I recall seeing warnings about these kind of measurements.

I would research to see if this condition is disabling your airbag, and if not, leave it alone.

draser · Post by **draser** » 17 Jan 2015, 16:20

It's fine, we tested airbags for our seats the same way, i.e. using the ordinary ohm meter, until we received an "industrial grade" one made by this company which actually tested the meter wires and subtracted from total reading. I work for a car seat builder. Reason is, the current applied is so small way below the trigger point.

rlrhett · Post by **rlrhett** » 02 Mar 2015, 17:50

precopster wrote:On the '99 model V70 in which I used a '95 seat I wrangled four 10ohm resistors in parallel to provide about 2.5 ohms overall. The SRS system accepted that.

Beware that connectors collect corrosion and may need a clean 10 years after manufacture. Then just re-assemble and clear codes

Did the exact same thing, and now I have a new error:

"Capacitance too high"

WTF? What now? Does anyone know what this means and how to fix it? I am loosing patience with this car. I fix one thing only to find a new error. None of these errors make a particle of difference for actually driving this car. It's like having software that is constantly pestering you to upgrade for just $49.95...