The dreaded airbag light has always been the modder’s enemy when fitting an aftermarket steering wheel or seats on any modern car and that’s for three main reasons…
First having it on or flashing is an instant MoT failure in the UK, which isn’t good. Second, your car will automatically disable the rest of its airbags, which is worse and, the real clincher is, that little bastard will inevitably start to get on your tits after about 3-miles. Here’s how to sort it out…
Prevention is better than cure, so if you can stop the light coming on in the first place, it can save you time and expense later. Factor this bit in as part of the job you’re doing and get everything ready. The basic premise is the same for both seats and steering wheels, you need to trick the car into thinking the airbag is still fitted. To do this you’ll need to fit an electrical resistor before you reconnect the car battery or turn the key for the first time. A broken circuit or wrong resistance will either tell the car the airbag is missing, or that it’s faulty, and this will trip the light.
Unfortunately it’s not a ‘one size fits all’ solution with resistors. They all have different values of resistance (measured in OHMS) and this needs to be specific to match the resistance of the airbag you’re taking out of the circuit. The value generally changes between car models and manufacturers so a little forum hunting will be needed. Don’t worry too much though – someone has always done it before.
Where to get them
When you know which resistor you’re after it’s usually a case of hitting your local Maplin or tracking some down online. Their saving grace is that they’re cheap, normally well under a quid a piece, so don’t be fooled by all these plug and play kits you see for a tenner or more – what do you think they’ve got inside them?
Ready Made Solutions
Sometimes, if you’re really lucky your part might already come with a free resistor kit. MOMO, Cobra Seats and a few other manufacturers offer these, the vast majority don’t.
Unlike most electronics jobs this one isn’t even close to rocket science. You just need to put the resistor across the circuit, that’s it. There’s two established ways of doing this when you’ve located the airbag feed, either solder it into the wires, or simply push it into the plug and tape it up. Just make sure the resistor is insulated with some tape, and secure enough so it can’t come out.
Light on already?
So you didn’t know all this and your airbag light is already on? Don’t panic, they can always be turned off. Again it’s time to do your research online because, depending on your car, sometimes you can get away with resetting the light yourself by following a certain procedure of key-turning or pressing buttons in a specific sequence. For the most part though you’ll either need a specialist diagnostic scanner to do the job or will have to take a trip to a local garage and hand over a few quid. Steer clear of the main dealers for this – most will really pull your pants down on the price.