Air Bag Light in Disguise

[Gonzo]

Air Bag Light in Disguise Gonzo 2011

Sometimes I wonder if the things I find wrong with some of these cars are just there for me to find out how ridiculous some people can be. I've got to question the thought process of the brilliant ideas that some people can have, just before total stupidity takes over. I gotta ask… "What were you thinking?"

 

The other day I had a late 90's GM in the shop. The owner had recently bought it off of a small car lot, and had no idea of the history of the vehicle. It was one of those "great deals" that he couldn't pass up. Why is it these "great" deals always have some sort of catch to them? Maybe it would be a good idea to have it checked out before you buy it. After looking at it, I might tell you to "pass it up". Honestly, I'll never understand why someone will buy a used car when they know nothing about it, or decide after they buy it to finally have it checked out … but they do.

 

This particular creation had some strange problems. It had a strange battery drain. At first glance all the instrument cluster warning lights, interior lights, and all the electrical functions seemed to be working correctly. There was a drain, a good one too. Strong enough to drain the battery in a day, or so. Finding the solution actually was going to lead to an even bigger problem.

 

Narrowing it down by watching the amp meter for the parasitic draw value, and pulling fuses till the numbers dropped back into factory specs was the next procedure. Of all things, it ended up back to a crossed up circuit between the air bag system and the charging system. I decided to check the air bag system for codes.

 

This is interesting, it's off line. No communication with the crash box. Hmmm, I'm a little confused, because I know I saw the air bag light come on and go off when I pulled it into the shop. Turning the key off, and then restarting the car didn't help me much, because the air bag light was on… and then off. But then, maybe it did. Like I said, the light came on, and then went off… hey, wait a minute isn't there supposed to be a few seconds before it goes off? Isn't this how it verifies its systems are functioning properly? I thought so. So, what's going on here?

 

As a technician I'm trying to follow the codes, the diagnostic charts, and the operating description of the system I'm working on. This particular problem wasn't following the chain of typical scenarios. Take in account this whole thing started off because of a battery drain… I'm really starting to scratch my head over this one.

 

I had a lot of different ways to go with this one. I could try and follow the draw a little further, or I could chase the problem from the air bag side of it. Maybe, it will all lead to the same problem. For my money I think I'll work on it from the air bag side of the problem.

 

The air bag fuses were all good, and the light did come on in the dash. So, I decided to pull the air bag diagnostic module out and pin check the leads to see if that lead anywhere. My first check on any system is the positive signals and then the grounds. Why's that you ask? Because a loss of ground can be seen as an open lead, and if the positive signals are there, you'll actually find a voltage signal on the open ground. That's what electricity wants to do… find ground, and find the shortest path back to the source of the voltage.

 

In this case they were all there, but when I checked the leads to the instrument cluster the voltage was coming towards the crash box rather than to the cluster. What now? (I love my job, I love my job, repeat as necessary) I guess I better pull the cluster and check the wiring from there back to the crash box and see if that leads anywhere.

 

After pulling the dash it didn't take a rocket scientist to see what the problem was. On the back of the instrument cluster somebody had cut the circuit board line to the air bag light, and then added a soldered-on wire to the charge light. So when the charge light was on, so was the air bag light. Once the car started (providing the charging system is working correctly) the charge light would go out, and so would the air bag light. Huh???

 

You can imagine my "mechanical language" was not for the faint of heart when I found out what was going on. It seems some genius didn't want to replace the air bag module, so they invented their own air bag warning light instead. Brilliant stupidity… I think that's the best way to explain it. I can't imagine somebody went thru all the trouble to deceive the buyer of this car for a safety issue such as air bags. It should be a criminal offense.

 

After undoing the homemade airbag light, the draw was completely gone. Now the only thing to do was to replace the air bag module to bring it back up to working order. I'm not saying anybody would have caught the problem at first glance. It was a well thought out deception. If you were not intentionally looking for an air bag light delay, I don't think you would have caught the problem.

 

Leave it to some unscrupulous dork out there to try something like this. But, I still think it is a good idea to have the car checked out prior to buying it. Maybe, just maybe, you can spot problems like this before you own the problem.

 

 

these stories are here before finally editing. Your comments are welcome and always love to hear from everyone. If you have a similar story, let me know.

Watch for my articles in several automotive trade magazines. Gonzo

 

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Edited February 26, 2011 by Gonzo

[xrac]

That was a pretty sharp crook on that one or a used car dealer telling an unscrupulous tech to just fix it where the light didn't stay on. You see a lot of shenanigans from some used car dealers. There are a few in our town that will not let a customer bring a used car to us for a pre-purchase inspection. Guess why? We had one used car salesman start insulting us when we found problems on Porsche he was trying to sell and my service manager almost physically threw him out.

[CARMandP]

Wow, that's a new one on me. I have never seen that stunt pulled before Pretty smart if you ask me. (and yes it should be illegal)

[Gonzo]

uote name='CARMandP' timestamp='1298740355' post='9530']

Wow, that's a new one on me. I have never seen that stunt pulled before Pretty smart if you ask me. (and yes it should be illegal)

It really should be illegal in every state.

[Gonzo]

That was a pretty sharp crook on that one or a used car dealer telling an unscrupulous tech to just fix it where the light didn't stay on. You see a lot of shenanigans from some used car dealers. There are a few in our town that will not let a customer bring a used car to us for a pre-purchase inspection. Guess why? We had one used car salesman start insulting us when we found problems on Porsche he was trying to sell and my service manager almost physically threw him out.

 

The people that would even consider buying a vehicle under those circumstances are (in my opinion) just as bad as the salesman that won't let them get it checked out. Unbelievable... and YES, I HAVE physically thrown used car salesman out of my door. I know exactly the type you're talking about.

Edited February 26, 2011 by Gonzo

[DewayneP]

I don't know for sure, but I thought tampering with an airbag system and not letting the purchaser know IS illegal? That used car dealer set themselves up for a lawsuit if their customer was ever in an accident and the airbags didn't work.

[Gonzo]

Here's what I found out Dewayne. tampering with the air bag is a choice of the owner, you own the car (not renting) so it's your choice.. you can even request to have the bag turned off for reasons of height, health, or disability. Even if the owner is a used car lot. however, knowingly selling a car with a defective air bag system and not telling the new owner is .. well, in some cases illegal. But, the way it's worded (typical politics) the phrase "knowingly" becomes the "escape clause" .

 

But I'm with you... it ought to be illegal, and if a so called "professional" sale is taking place... then things like this should be checked out. This isn't the 50 or 60's where we didn't even consider seat belts as a requirement... this IS the time when as much care is taken to protect the driver and passengers as well as fuel mileage.

 

It's just sad to find what I found on that car... are real eye opener to the other side of car repair.... the illegal side.

I don't know for sure, but I thought tampering with an airbag system and not letting the purchaser know IS illegal? That used car dealer set themselves up for a lawsuit if their customer was ever in an accident and the airbags didn't work.

[TheTrustedMechanic]

Here's what I found out Dewayne. tampering with the air bag is a choice of the owner, you own the car (not renting) so it's your choice.. you can even request to have the bag turned off for reasons of height, health, or disability. Even if the owner is a used car lot. however, knowingly selling a car with a defective air bag system and not telling the new owner is .. well, in some cases illegal. But, the way it's worded (typical politics) the phrase "knowingly" becomes the "escape clause" .

 

And therein lies the problem. Even if this dealer did have the chop job done the buyer has to prove the dealer knew it was "fixed" incorrectly. Good luck in getting that done. Any tech who would do that sure as heck isn't going to admit to it.

 

 

One of those buy-here-pay-here (screw job instant junk) car lots near my shop has their cars all "inspected" before sale. They even strongly suggest it to the customers. It's all a credibility thing. Convince the customer that the deceptive car lot is really honest because they let the customer have the car inspected. Well the car lot steers the customer to a specific shop. A friend of mine worked there (the shop not the car lot) and he told me that the "inspection" was very specific and he was NOT to "find" anything else except what the car lot authorized them to "inspect." Anytime I have a customer talk about buying a new-to-them used car I always tell them to have it inspected first. I try to impress the value of the inspection as a bargaining tool if anything is found wrong then they may be able to get the seller to pony up some $$ of the price. And at the very least they will knwo what they are buying. I tell them that if the dealer or seller refuses to let them have it inspected first WALK AWAY, there's a reason why they won't let it be inspected, they are afraid you will find something they don't want you to find.

 

Or like in the case of my mother-in-law's minivan, a Chrysler with the remote in the key head, the van had only one key. When the salesman dropped it off I asked if it had two keys and he said, "Yes, I only brought the one." I thought that was little fishy so I told my MIL to insist on having both keys BEFORE signing the paperwork. Well she didn't, so she had to go back and get the second key, programmed to the tune of $150.00+. But not being one to get pushed around, and having written many loans for this dealership when she worked at the bank, she talked to the sales manager and told him I was specifically told that there were two keys and the salesman had flat-out lied, so the sales manager graciously paid for the key. Had it not been checked out first she might have had to pay for that very expensive key.