2001 V70 Too early airbag deployment?

306V70 · Post by **306V70** » 25 Jan 2012, 16:26

Hello. This is my story.
I own a 2001 V70. 145000 Km. After replacing the famous ETM, a door lock the tailgate wiring and the A/C Condenser it runs fine. Found good information in this board. 1 Month ago my wife had a little crash into the back of a other car during "take off" on a traffic light.
No other visible collision damage than few scratches on the front/tail bumper but......all air bag's and belt tensioners fired, what means for me, that a perfect car has turned itself into scrap because repair is far too expensive compared to the value of the car. Same happened to a friend of our family ( V70 2004) He always had driven his car slowly til contacting the Garage wall. On a certain day....bang... - scrap. Safe the Planet.
It seems to me that Volvo has counters built in in all the ....CM's, programmed for self-destruction after > than 7 Years.

Is there anybody out there, having the same bad experience? A known problem or just bad luck? All the dealers around had the same answer with a smile: "That is for your safety". I can't agree. Not that slow / little impact force. (Before the V70 i had a Volvo 121 than a 740 for nearly 24 years. Never troubles. Real Swedish Tank's.)
My next car is probably a old Russian Lada.

Regards, M.

Post by **Ozark Lee** » 25 Jan 2012, 22:05

I'm not aware of any chronic problems with the Volvo SRS system but I am moving your post to the P2 V70 forum for some more specific comments.

...Lee

306V70 · Post by **306V70** » 07 Mar 2012, 15:36

Story goes on with my Blown Bags:
I found all the neccessary parts on a scrap yard. Same Car, same year, exept other automatic tranny and 2.4 litre instead 2.3 L as mine. All belts, all bags, dashboard and sensor module. (belts complete with harness.)
Airbag sensor has same Bosch P/N but different Volvo P/N.
Got some Questions:

1. Will the sensor fit my car as long as the Bosch P/N is the same? What car related datas are stored in this unit?

2. Is it possible to drive the car to a dealer (for clearing all the fault Messages)without connecting the sensor during this trip or
will this trigger a bunch of other fault messages or even stop the engine. All other stuff is allready replaced.

3. I read different storys about the sensor after it has triggered the bags/belts. Some says it has to be replaced, no other way, other tells me the dealer can reset it via diagnostic system if all other components are serviceable again, the next tells me sent it for crash data clearing to special shops???? What is the point?

If this all went well, i will may be refuse to buy a old Lada right now....

Thank you.
Regards M.

306V70 · Post by **306V70** » 18 Apr 2012, 16:34

Good news, not only complaining.

Today i made the first power-up after i replaced all bags, dashboard, belts and the control-module. For this first power-up , i installed for every bag igniter and belt a dummy resistor. (self-made, gold plated pins, 1% tolerance 2.2 Ohm resistors, because i don't want destroy a other dashboard)

Surprise: No SRS message nor any other fault indication.

It seems to me that a SRS fault is only stored in the SRS module itself and sent via CAN to the rest of the world.

So i will hook up everything as legal tomorrow and hope it stays like this. Except i screw something up or one of the units i got from the scrap yard is bad but actually they are newer than the removed ones.

I also found a handwritten label on the back of the "blown" control module witch says: measurement 1: 0,7 / 2: 0,7/ 3: 0,7. This means to me something was already going on with this system.

The job itself was not too bad, intelligent engineering, compared to some aircraft i work on. But without the maintenance manual i would have had destroyed a lot of plastic trim panels. Most important: Park the car, pull the key, go for a long coffe brake, come back and disconnect the battery neg. terminal, make sure it stays like this, go for a other coffe-brake, than start working.
MM says that the key must be in pos II for reconnecting the battery, nobody in car. So i did.

Regards
Markus

Post by **jimmy57** » 18 Apr 2012, 17:27

Glad you got it all repaired.
Airbag deployment is not something you can look at and make any determination. It would take yet another decelerometer mounted in car recording the forces to really know if the deployments were at lower than correct decel levels.
As another already said, Volvos are not known for improper deployment.
The key on battery reconnect is only a safety thing. There is no bag or belt to harm you back by that battery in the event something is wrong and bags deploy on first power up.

306V70 · Post by **306V70** » 19 Apr 2012, 16:40

Would not give it an other try. Too much work and money.

For the passenger A/B i still have the dummies installed. Like to make a few kilometers (miles) first. As a solo pilot.
I'm still curios about, why that Thing went off for nothing at all. And as already told, not only mine, also the one of our friend.
Planned obsolescence is still in my mind

...even if you go to Germany for repair, this is about 6500 Euro minimum. (8500 US Dollar) So the Car is Scrap or self-made if you know what you are doing.

Does any body know if Volvo dealers with there test equipment have the capability to "bench-test" the control modules?
What happens if the control unit detects a fault, - after the proper repair, does the SRS light / message disapear after successfully self-test or does a dealer have to clear a fault memory? (My old Peugeot 306 does it by it self. Fix the problem - self-test ok, light off.
That's the way it should work. But today??

Heja Volvo

Markus

Post by **jimmy57** » 19 Apr 2012, 17:44

On the early systems with dual airbags almost all deployed both. The second take on this that Volvo used on your car was multiple level belt and airbag staging.
First level gets belts only if seat belt buckled. If a seat belt is not buckled (also empty seat) then the airbag is deployed as there was not a way to sense occupation of the seat.
For second level the airbags are deployed along with belts. There is a time delay for front bags based on crash energy level. As crash force goes up the time delay, which is a very few milliseconds max, gets shorter up to no time delay for severe forces.
The bag needs to last longer but be less pressured for lower crash forces and last less and be firmer for higher crash forces.
The passenger seat getting an occupancy sensor came later and not in all markets. Occupancy sensor cuts off the passenger airbag. This was a legal requirement as some people have no choice but to have child seats in the passenger seat and the OWS is how the air bag gets inhibited when child seat or low weight humans get in that seat. The child seat gets strapped down and pts force on the OWS but there is a belt tension switch on these and a properly installed infant seat will apply force to cushion and the OWS below it and the belt will get taut from cinching seat with it. The Passenger Airbag Off warning will be lit letting the driver know the child seat is secure and the airbag is off.

306V70 · Post by **306V70** » 22 Apr 2012, 07:28

Thank you for your Information,

Does this in my case mean, that if i allwys have the FWD Passenger Belt in its buckle, no matter if sombody is in the seat or not,
doing so, could eventuelly prevent the pax airbag from deploying for nothing, and instead of it, it blows the Belt wich would mean less work and maybe money too?

Was there been out a SRS system software change since introduction of this system? Model 2001.
(sorry my swiss hillbilly english)

Markus

Post by **jimmy57** » 22 Apr 2012, 07:56

Buckling that belt would stop the RH airbag if the crash was 1 st level.
There haven't been any software changes that I know of.

306V70 · Post by **306V70** » 19 May 2012, 04:52

Thank you all for your comments.
Till now everything works fine.