New airbag/SERV light solution (?) - passenger airbag on/off switch

[J.B.]

I haven't seen anyone mention this when I've been searching ways to fix the airbag and SERV light, so I thought I'd make a thread for anyone who has tried everything else. Best of all it takes 10 seconds, costs nothing and needs no tools!

I tried the usual quick stuff to fix this which didn't work so I thought I might as well try the passenger airbag switch on the passenger door as it's part of the system. All I did was switch it to the 'off' position with the key and turn the ignition on. Both airbag and SERV lights went off! As expected, the passenger airbag light came on. I then turned the ignition off and went back to the passenger door and put the passenger airbag back on. Turned the ignition back on and there were no airbag or SERV lights!

Problem solved! Really thought I was going to have to spend money to fix it, happy days Let me know if this works for anyone.

 

[J.B.]

Update: Not sure if anyone cares given the lack of replies, but I think I'm on to something.

So the problem is back intermittently and now one of 3 things happens.

1: Passenger airbag switched to OFF position. SERV and airbag warning illuminated. Passenger airbag light NOT illuminated. (i.e. the switch is not working.)
2: Passenger airbag switched to OFF position. SERV and airbag warning NOT illuminated. Passenger airbag light illuminated. (normal operation.)
3: Passenger airbag switched to ON position. SERV and airbag warning illuminated. Passenger airbag light NOT illuminated.

I cannot replicate any of these as I please, so I'm looking squarely at the switch being faulty (hopefully). Otherwise this is going to get expensive. Just bought a replacement switch from Ebay.

 

[Hawk182]

let us know how you get on, i had this with my old car but it was down to the wiring under the passenger seat. (which i soldered btw)

 

[J.B.]

Will do. It can't be the seat connections on mine as I have a Cup, so it's either this or something complex probably.

Forgot about the 4th condition: Passenger airbag switched to ON position. SERV and airbag warning NOT illuminated. Passenger airbag light NOT illuminated. (i.e. it appears fixed, but then returns later after restarting the engine).

 

[Darklite]

Take the passenger grab handle out, check that the block connector underneath the airbag key is pushed all the way in.

Mine was loose, pushed it in, no more lights.

 

[J.B.]

If it wasn't dark I'd be straight out there. Will investigate tomorrow, cheers. If that fixes it it's no biggy to have spent just £4.40 on the replacement switch. You just have to love how cheap parts are for these cars.

 

[J.B.]

Take the passenger grab handle out, check that the block connector underneath the airbag key is pushed all the way in.

Mine was loose, pushed it in, no more lights.

Well nothing in there looked loose so I just took out the airbag switch and gave it a wiggle. No more lights! Wonder whether they'll come back.

 

[Darklite]

Take the plug out and see if there is any corrosion on the pins, or a loose wire on the plug end.

 

[J.B.]

Oh it's getting better. No lights with just the ignition on, but when I start the engine the lights are back. FFS.

I'll try cleaning the pins.

 

[Darklite]

Bad connection somewhere, maybe a dry solder joint on the plug leading to the airbag switch?

Have you checked the wiring under the seats, give it a wiggle, so if the light comes on/off?

 

[J.B.]

I have checked the seats but as far as I know that particular fault cannot occur on a cup since it has no airbags in the seats. I'm almost certain it's this switch in some way. I will give it a good look over and clean everything up.

 

[Darklite]

Do you have any friends with a 172/182?

Take out your friends grab handle, plug it into your wiring. If the fault goes away, you will know that the switch is faulty. If it doesn't, then the problem lies elsewhere.

 

[Stu-]

Check the plug for the steering wheel, under all the plastics behind the wheel. Mine had came unclipped somehow.

 

[J.B.]

Good plan using a mates. Either way, I should have my new switch tomorrow.

Will also check behind the steering wheel. Cheers Stu.

 

[Darklite]

I think stu has a good point. Pull the top cover off, from behind the clocks and the wheel.

Make sure the plugs are firmly engaged, i think there are two, one yellow, one black.

May be worth disconnecting your battery first for 30 mins. I think one of these plugs is for the airbag. You don't want it going off!

 

[J.B.]

I think stu has a good point. Pull the top cover off, from behind the clocks and the wheel.

Make sure the plugs are firmly engaged, i think there are two, one yellow, one black.

May be worth disconnecting your battery first for 30 mins. I think one of these plugs is for the airbag. You don't want it going off!

New switch did nothing

You say 'behind the clocks and the wheel', but do you mean behind the wheel but infront of the clocks?

 

[J.B.]

So apparently this fault can occur because of the seats on a Cup due to the pretensioners! I just moved the seat around and got the light to go off... again. Time to break out the soldering iron I reckon.

 

[J.B.]

All wires under the seats that went through the gray connector are now soldered. The problem is still there, ffs.

They still go out from time to time, usually when the seat is moved. So now I'm thinking it's something at the pretensioner end. To make matters worse, the passenger airbag switch on the door doesn't turn off the airbag (doesn't display the 'airbag off' light in the cluster.

Borrowing a mates OBDII this week, this is getting seriously annoying.

 

[J.B.]

I'm out of options now, I need to get this into a garage to be fixed as the MOT runs out on Sept 16th. Where should I take it? Nick at Diamond, Fred, someone else?

Checked the steering wheel, checked the door switch and soldered the connectors under the seat. The switch no longer affects the passenger air bag as it should

 

[MicKPM]

Honestly, guess work with problems like this does nothing but frustrate you and empty your wallet. Just get it plugged in and go from there chap.

Mick
Diamond Motors