Today’s cars and trucks are very safety oriented. With the addition of many accident prevention items, there has also been a lot of new airbag technology lately. Everything from side airbags, which protect in a side impact, to the latest head curtain airbags which help in a rollover accident and also provide more safety on side impacts as well if so equipped. With all this new technology, comes a lot more components to the system, wiring and connectors. Take for instance the 2010 and up Chevrolet Malibu.
With the addition of driver and passenger side impact protection, which basically means there is an airbag in each of the front seats, there is much more wiring in the seats and floor. This added wiring and related connectors has had a few problems as of late. What is happening, is with the back and forth movement of both the driver’s and passenger’s front seat, this is causing tension on the side airbag connectors underneath the seats. Now, we all have to get in and out of the backseat, put our belongings back there, and the kids as well! The thing is, there is only so much room for the wiring harness to have play in it without it being extremely loose and having to lay on the floor.
As the seat moves, it pulls ever so slightly on the harness that comes out of the floor and goes to the seat. Airbag connectors are probably the most sensitive connectors on any vehicle, and even the slightest movement can result in the terminals inside the connector to not have full contact. With this movement, and the terminals in the connector not fully touching, that adds resistance to the circuit. The SDM (airbag computer) senses this resistance and will set a trouble code for whichever seat is causing the problem. It is always looking for a certain amount of resistance in the circuit, along with the rest of the system to determine the state of health of the airbags and if/when deployment is needed. When the reading is just a little off, the computer can’t do it’s job correctly and alerts the driver by setting the airbag light on and usually a ‘service air bag’ message in the driver information center.
General Motors has a fix for this problem by having us technicians wire in new style connectors. These new connectors are a bit larger and heavier duty than the smaller previous ones. The terminals are much larger which helps maintain a positive connection, even with seat movement. I’ve personally done this repair to probably 30 cars or more! This usually does the trick and the customer does not have to worry about any side airbag problems any more.
A little side note to this story, and an added problem that the customer usually causes on their own….don’t shove large objects under either front seat!! I’ve had cars come in with the airbag light on, only to find an umbrella, shoes, or a large water bottle shoved underneath one of the seats!! This almost always dislodges the airbag connector and can set the light on. Remember there are delicate electronics under there! Especially now with Passenger Presence Systems, the underside of the seats is jam packed with modules, wiring, connectors, and other electronics. Keep a keen eye on that and you should never have a problem.
I’m having a problem with the horn on my 1999 Chevy Malibu LS. It will not honk from the steering wheel. When I lock the doors with the key fob, it will honk signaling that it has locked. We tried switching the relay, but it didn’t help. Any ideas?
Just a moment and let me look at few things please…
Well, the problem would not be in the relay or anything after the relay- including the wiring and the horns, since they do function. Both the remote circuit and the horn pad circuit go through the relay. The most likely problem is in the horn pad or horn contacts.
How do I work on the steering wheel without setting off the air bag?
You will need to remove the Airbag fuse and disconnect the connector under the steering column. It is a yellow connector.
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