Anyone Had An Airbag Wiring Loom Replaced?

[WatchfulEye]

Hi. My 2006 edition 220d has got the air bag light on intermittently. It's the well known manufacturing flaw on the wires to the driver's knee airbag squib. This was subject to a dealer alert.

The problem is that the car has got a ton of miles on it, about 120k and it's now 6 years old, so well out of warranty (although these are getting warranty repairs in the US, where the air bag warranty is 7 years).

Basically, the airbag wiring loom needs replacing; this is the only repair the dealer will offer. It's a £2k part, and about £2k labour.

I'm wondering if anyone has had this repair done independently. The part should be purchasable by any garage, and it just needs an auto electrician who can strip down the car to replace the loom; who I'm hoping will be rather cheaper than the dealer - who estimates it to be a full 2 day job.

Anyone know of someone in the Greater Manc area, who'd be up for this sort of a job?

[Shepherd]

I had the same light. No independent electrician wants to even touch it as they don't like working with Lexus airbag systems for some reason. I got toyota VCi cable from eBay (hongkong) . this cable came with pi*ated copy of toyota techstream software that runs on windows XP only. this is the only software that can clear the air bag code. I cleared the airbag code and the light went away for a few months. Now its comes back every few months, I just clear it with the VCI cable. I have heard this happens because some thing like kids toys or water bottle etc gets under the seat and presses against the airbag wires causing them to trigger a malfunction light.

[WatchfulEye]

I've got the same cable. The thing is though, you don't need the cable to clear the light. The light goes off automatically when the fault disappears.

It's possible for bottles and stuff under the seat to press on the wires, but the air bag connectors are very carefully designed, so unless you actually dislodge or damage the wires it shouldn't be much of a problem.

In my case, the problem is a well known design fault in the wiring; there's too much tension on the wire that goes to the driver's knee air bag and it cracks. I've checked the codes (and it's this circuit) and I've inspected the wire, and I can see that it's under tension and pulling out of the connector. (This design flaw affects the 2005-2007 2nd gen IS models, but is fixed in the 2008+ models; the repair involves replacing the air bag wiring with the redesigned wiring loom).

Technically, it's a trivial fix - just replace the wire, or solder in an extension to take the tension off. But, there's no way I'm touching an air bag system while it's in the car; and I don't have the experience, or tools, to strip down the entire cabin to get the loom out, so that I can repair the loom in a safe environment when it's out of the car.

So, as it's not a DIY job, I'm just going to have to pay someone to do it. I'd rather pay an independent mechanic to strip down the cabin, and pull the old loom out, and install the genuine lexus replacement loom (which has been redesigned to take the tension off the knee bag wire); than pay the dealer to do the same job at twice the price.

I suppose, technically, I could hire someone to pull the loom out, and the I could repair it, and then refit it - but I doubt I'd find someone who'd agree to that, and if I'm going that far, I might as well get the genuine upgraded part.

[Shepherd]

as far as I know the genuine part costs like £700 . For a wire, I would never pay this much. Is it the passenger side knee air bag, what is the code you read?

I am getting to a point were I may just trade in my 220d for a 250 or an older GS

[normski2]

as far as I know the genuine part costs like £700 . For a wire, I would never pay this much. Is it the passenger side knee air bag, what is the code you read?

I am getting to a point were I may just trade in my 220d for a 250 or an older GS

Did the same myself... lets just say ...I rather like the 250!

[WatchfulEye]

as far as I know the genuine part costs like £700 . For a wire, I would never pay this much. Is it the passenger side knee air bag, what is the code you read?

The code is B1861 - drivers side knee airbag squib open circuit.

[Geoffers]

Have you tried just extending the cable yourself to take the tension off? Done properly there really is nothing to worry about.

It's an awful lot of money and a big job just for that. I would look at extending if you can see where the tension is.

Is it at the knee airbag or at the control ecu?

[Shepherd]

Hi, here is picture of the squib J20. Is it the same place in RHD vehicles?

[WatchfulEye]

Yup. That's basically an exact mirror image of the wiring on the RHD models. The squib is on the door side of the DLC.

I can reliably trigger the air bag light if I unclip the under dash and let it sag under its weight (unfortunately, the retaining clip is broken - it looks like whoever I bought the car from had been tinkering in this region, probably he'd had the air bag light on, and sold it fast after propping up the dash). I first realised there was a problem after hooking up a techstream cable; the act of plugging it in, had dislodged the dash from it's flimsy support, and that was sufficient to trigger the light.

Once I prop it up properly, and use a string or something to attach it to something more rigid, the light goes off and stays off. So it's obviously the connector, or the wires immediately up to it - possibly, they've been strained by a broken dash attachment clip, or possibly the clip was broken by someone trying to investigate the air bag. I don't know which.

[Shepherd]

@WatchfulEye -> did you finally manage to fix it? or did you swap your car to IS250?

[Karmabim]

I read these articles with interest when the airbag light on my 2008 IS220d started remaining lit. I worried that it may need a rather expensive loom change but first I spoke to my friendly garage man. He asked if I had moved the seats more recently, which I had, he said it was more likely to be the wiring under the seat playing up. I checked the connections and made sure the plugs were all pressed home. To my delight the lamp went out but only for a few days. Subsequently fiddling with the cables under the seat would sometimes work for a day or two so I know the problem is somewhere in the seat part of the loom or in the seat itself. As this must work for the MOT I have to get it fixed one way or other, so I have 'invested' in a workshop manual off eBay. once this arrives I will try to work out which wires/plugs are associated with the problem and hopefully fix it. I will post my results in a few days.

[Shepherd]

https://onedrive.live.com/redir?resid=56579C4329457349!80916&authkey=!ABuOXifGwZJQo0I&ithint=file%2c.iso

Better invest in a toyota VCI cable from eBay to figure out exactly what airbag code is stored in the airbag ECU system