940 SRS light

360beast · Jan 11th, 2020, 17:51

Hello all

My mates 940 needed a new rack so we fitted one, during fitting our other mate decided to be a pleb and jump in the car and spin the steering wheel over and over again like a child. We then started the car up after the change and the SRS light came on! Took the air bag squib off and it was knackered so I gave my spare one to my mate and he has fitted it. Pulling fuse number 1 for a over a minute does nothing and the light is still on.

Any ideas what could be up with it? We need to figure out how to read fault codes on it too.

It's a 1995 b230fk estate.

Laird Scooby · Jan 11th, 2020, 19:16

Diagnostic connector "B" under the bonnet is where you read the codes Luke, as for your mate that kept spinning the steering wheel, in future cable tie his hands behind his back before letting him near the car!

According to Volvo, any more than 3 turns in either direction will kill the rotary coupler/clock spring/contact reel/squib so it's a fair bet your mate murdered the original.

Are you sure the one you gave your mate that owns the car is ok? Could simply be it's held and recorded the fault from the first one that died so the replacement might be fine but you need to clear the fault first using the diagnostic connector.

I can't find any evidence that the SRS ECU has power from fuse #1, as it's (supposedly) a safety critical item it's possible it has its own internal memory in the SRS ECU that needs clearing - i know of a few other cars like that. Good call pulling fuse #1 to try and clear the memory though!

griston64 · Jan 11th, 2020, 20:36

Could a 95 car have the OBD port in the armrest Dave ? My 96 does

360beast · Jan 11th, 2020, 20:50

Do you know what sort of connector is needed to read the codes Dave?

The one I gave him was from my breaker and I just checked in the video of it starting up, no SRS light on the dash. "New" one has resistance inside like a clock spring where as the old one spins freely.

Now that you have said about it not running through fuse 1 that would make sense, I will see if there is a separate fuse for it and pull that.

Laird Scooby · Jan 11th, 2020, 21:22

Quote:

Originally Posted by griston64

Could a 95 car have the OBD port in the armrest Dave ? My 96 does

It might have Mark but the Volvo sources i was using suggest it's the underbonnet code reader, the 96 model had the armrest mounted not-quite-OBD connector.

Quote:

Originally Posted by 360beast

Do you know what sort of connector is needed to read the codes Dave?

The one I gave him was from my breaker and I just checked in the video of it starting up, no SRS light on the dash. "New" one has resistance inside like a clock spring where as the old one spins freely.

Now that you have said about it not running through fuse 1 that would make sense, I will see if there is a separate fuse for it and pull that.

https://www.volvoclub.org.uk/faq/ElectricalSRS.html

If it's the one i'm thinking of Luke, you won't need any connectors - have a look at the link there and follow the "1992+" code reading where it explqains about the connector box and the probe and LED under the bonnet near the suspension turrets.

The insides of the roatary coupler are basically a clock spring or 2 to transmit power on different contacts. They're fairly robust and durable until some muppet goes silly on the steering wheel or until they're fitted incorrectly. Ideally when removed, the front wheels should be in the straight ahead position and when removed, a piece of tape should be wrapped round the inner and outer halves to prevent them "unwinding".

If the suspect one spinds freely, it's TARFU.

I couldn't find a separate fuse for the SRS ECU memory, it has power from the ignition switch in positions 2 and 3 but seemingly no other permanent (memory) feed.
I think the only option is to read the codes and reset using the underbonnet box/probe combo.

Fingers crossed there's no damage done to the ECU.

360beast · Jan 14th, 2020, 17:37

Well we have had a look and can't find any led readout box thingy in the engine bay but there is a connector under a blank in the arm rest so I guess we need a code reader for it.

My mate pulled the under dash trim off to have a look under there for a connector and found the previous owners improvements of an alarm are up the same standard as the rest of the "improvements" and the wires have all been twisted and taped. Time to go through this car properly and remove all the b0ll0cks that has been added and remove all the suspect wiring.

Horn has also stopped working now.

Jan 11th, 2020, 19:16	#2
Laird Scooby Premier Member Last Online: Yesterday 23:44 Join Date: May 2012 Location: Lakenheath	Diagnostic connector "B" under the bonnet is where you read the codes Luke, as for your mate that kept spinning the steering wheel, in future cable tie his hands behind his back before letting him near the car! According to Volvo, any more than 3 turns in either direction will kill the rotary coupler/clock spring/contact reel/squib so it's a fair bet your mate murdered the original. Are you sure the one you gave your mate that owns the car is ok? Could simply be it's held and recorded the fault from the first one that died so the replacement might be fine but you need to clear the fault first using the diagnostic connector. I can't find any evidence that the SRS ECU has power from fuse #1, as it's (supposedly) a safety critical item it's possible it has its own internal memory in the SRS ECU that needs clearing - i know of a few other cars like that. Good call pulling fuse #1 to try and clear the memory though! __________________ Cheers Dave Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........

Jan 11th, 2020, 20:36	#3
griston64 Premier Member Last Online: Apr 21st, 2024 14:28 Join Date: Jul 2012 Location: Lenzie	Could a 95 car have the OBD port in the armrest Dave ? My 96 does __________________ V70 D5 SE Geartronic 215bhp Saville Grey 2012MY 940 LPT Manual 1996 740 SE 1990

Jan 11th, 2020, 17:51	#1
360beast Go redblock or go home Last Online: Today 00:59 Join Date: Feb 2012 Location: UK	940 SRS light Hello all My mates 940 needed a new rack so we fitted one, during fitting our other mate decided to be a pleb and jump in the car and spin the steering wheel over and over again like a child. We then started the car up after the change and the SRS light came on! Took the air bag squib off and it was knackered so I gave my spare one to my mate and he has fitted it. Pulling fuse number 1 for a over a minute does nothing and the light is still on. Any ideas what could be up with it? We need to figure out how to read fault codes on it too. It's a 1995 b230fk estate.

Jan 11th, 2020, 20:50	#4
360beast Go redblock or go home Last Online: Today 00:59 Join Date: Feb 2012 Location: UK	Do you know what sort of connector is needed to read the codes Dave? The one I gave him was from my breaker and I just checked in the video of it starting up, no SRS light on the dash. "New" one has resistance inside like a clock spring where as the old one spins freely. Now that you have said about it not running through fuse 1 that would make sense, I will see if there is a separate fuse for it and pull that.

Jan 14th, 2020, 17:37	#6
360beast Go redblock or go home Last Online: Today 00:59 Join Date: Feb 2012 Location: UK	Well we have had a look and can't find any led readout box thingy in the engine bay but there is a connector under a blank in the arm rest so I guess we need a code reader for it. My mate pulled the under dash trim off to have a look under there for a connector and found the previous owners improvements of an alarm are up the same standard as the rest of the "improvements" and the wires have all been twisted and taped. Time to go through this car properly and remove all the b0ll0cks that has been added and remove all the suspect wiring. Horn has also stopped working now.

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