jsaunde2

OK, this is for someone who knows their stuff. Long version then short version

Long version:

I recently had tires replaced on my car and had one of the LTPWS sensors get broken. No big deal it's happened before. The manager of the tire shop asks me to take it to a dealer to have it repaired and he will reimburse me. Fine, but here is where it gets interesting.

I take it to a dealer who sits on it for three days and finally calls to tell me that all four sensors are bad and it will be a little over $1600 to repair. I knew this was crap as I have dealt with LTPWS sensor replacement several times so I told the guy I would come pick up my car right away.

I took the car straight to another dealership who looked at it the next day and said it needed one sensor, as I had expected. The part was ordered and the car repaired in a few days.

I gave the first dealer the benefit of the doubt and drove the car for about a week to ensure that the LTPWS light didn't come back on. So then I go into the first dealership to discuss their attempted fraud. I talked with the GM and the service manager. The service manager was overtly rude and implied that I didn't know what I was talking about.

He then had the shop foreman come out with a tech-2 to read the codes off of my car. I thought this was pretty dumb as the dealer that actually repaired the car should have, and I believe did, clear the codes after the repair. The shop foreman plugs in the tech-2 and screws around for a while, then he announces that there are no codes and the other dealer must have cleared them.

Then the service manager heads back in to get my reciept and see what codes they had said were on the computer when they looked at it. A few minutes later, when the service manager came back out, the guy looking at my car has somehow gotten the service LTPWS light to start flashing the codes. I watched it flash 24,34,and 44 then I stopped watching. They then announce that they can have no idea what's wrong with my car and that the sensors may still be damaged and that they did nothing wrong. I then ask them how they can possibly think they did nothing wrong when they told me I needed to fix four times as much as what solved the problem.

Short version:

Bad dealer says all four sensors are bad. Good dealer says one sensor is bad, replaces one sensor, light remains out, car is fixed.

Go to bitch at bad dealer. Bad dealer reads codes with tech 2, says no codes other dealer must have cleared the codes, duh. Five minutes later same guy working tech 2 gets the car to start flashing codes through LTPWS light. I see codes 24-34-44 before I stop watching. Dealer claims no wrongdoing.

Questions:

1. Under what conditions are the LTPWS sensor codes stored in the computer, i.e. after failure of a sensor does the code remain until cleared manually or will a set number of cycles erase the code?

2. Further in the vein of question 1, are the codes ever in the computer if the service LTPWS light is not illuminated?

3. Is it possible to use a tech 2 to cause all possible DTC's to flash? For example, could the tech have caused the car to display the codes in some sort of diagnostic procedure for the scantool without the codes actually being stored in the car computer? For further information the tech 2 displyed "Flash DTC's" when the codes where being flashed.

4. Does the tech 2 not simply give a display on it's screen of the DTC's rather than causing them to be flashed through the idiot light? I know that the snap-on scanner does this for most codes so I am curious why this would be different.

5. What does GM think of fraud by its dealer service departments?

Thanks for your help.

Jason

John Row

I'm no TECH II expert (I really want one of these things). I've only play with it a short while turning cylinders (spark and injector) on and off. It's a pretty powerful tool, I'd be dollars to doughnuts that it can make any light in the car flash.

Recommendation, go to the good dealer, don't go to the bad dealer.

jsaunde2

I mosly want this info for my own knowledge and so that I am fully informed when I talk to the attorney general, GM, and the local news. I was hoping to get a decent response from the dealer and then I would drop it.

SInce they were a-holes I am going to spend some of my free time giving them a hard time. BTW, I am a law student so I have some idea what I'm doing in regards to this.

Jason

silver & red CE

How does the saying go, "Unleash the dogs of war", LOL. While you will cause minor pain to the dealer, I predict the AG, GM and the press will ignore this story. The situation won't be clear to any of them, the dealer will discredit you by showing anyone who shows up his mechanic's certificates and ask how a law student is a better expert...Save yourself the aggravation and drop it. You're a smart consumer, be happy for that.

Eric

merrick

I never used a tech2 either, but I pretty sure the fault codes will stay in the computer until cleared manually. I don't think they can make codes appear without an actual problem. Maybe the tech is not using the tech2 correctly in the first place. I would just use the good dealer and not pursue a lawsuit. Too many morons, so little time!

jsaunde2

I'm sorry but I would feel like a real poopie if I let someone else get duped by these people. They tried to steal $1200 from me. They may not have tried to use a gun but they sure as hell tried to steal it.

BTW The bad dealership was Champion Chevrolet in Austin, Texas. Do not give them any business whatsoever. They are crooks and don't hesitate before screwing you!

Jason Saunders

silver & red CE

Everyone here already knows dealers suck, that's why we do our own work, with a little help from out forum friends :cheers:

Eric

dlmeyers

OK,

I have a Tech1A (used before Tech2- which is 96 and newer I believe) with a 1996 Mass Sorage Cartridge update. The manual does not show a method for inserting codes. Not sure about Tech 2.

Computer modules occasionally send multiple codes. Not uncommon for Sective Ride Control units to send lots of codes, like 6 or more at once. You clear them and check for repeat. Battled with my 90's ABS module for 7 months. Ghosting code for Right Front sensor. Finally, the start checks for the pump assembly seemed too long and I replaced the module. Fixed it.

When you get multiple codes with the LTPWS, means you have to do some more checking. The receiver unit is "listening" for a diagnositic signal from each tire that must be received during a "Diagnostic Cycle". If the wheel signals do not report in during this cycle, "Service LTPWS" illuminates. With multiple codes set, as in all four wheels, this suggests to me the receiver is not receiving this test signal. Your "bad" dealer may not be that familiar with this system. It may be possible for the Tech 2 to generate this signal and see if the module receives the signal. Not sure. OBD2 test equipment (tech2) can generate some very sophisticated test routines. If one dealer keeps getting these codes, I would suspect a knowledge problem with the test routine.

If it were my car, I would focus on the receiver and attempt to rule it out. Clear the codes, drive the car, and see what happens. If no problems occur, drive on. Contact the GM service area advisor, tell them you think a certain dealer may need additional training on the Tech 2 and LTPWS diagnosis.

If you have the service manual, read up on the LTPWS, maybe around section 3E-9. The LTPWS can be very helpful. Don't have it on my car. Once had a tire leak and the right rear tire almost went flat. Driving around town, couldn't tell it. Felt lucky I didn't ruin a tire and rim.

Sounds to me like some dealer personnel haven't done their homework. Suggesting four bad sensors isn't realistic. Maybe lack of technical knowledge. Doubt intentional fraud. Maybe they really didn't want the job and gave you a rediculous price, knowing you would go someplace else because they lack proficiency repairing the system.

Hope this helps.

Let me know if you have any more questions.

Keep the greasy side down.

dlmeyers 90 coupe zf6 3 speed shocks

jsaunde2

The car has been repaired and has not had the service LTPWS in over a week including four long trips, Austin-Houston. There is not fault in the system and three of the sensors have been functioning properly for three years with the computer being cleared multiple times in that time frame. There is no reason that the codes should be stored in the system.

I am curious about "ghosting" codes. Are these codes that are erroneously generated and stored when there is no actual system fault?

They probably don't know what they're doing. I gave them the option of saying that maybe they needed to change their diagnostic procedure and they acted indignant and said they did nothing wrong.

If you ask me it is fraud to claim to be providing a professional service, advice/opinion on what is wrong with your car and how to best repair it, when you actually have no idea what you are doing. I know that being a mechanic has never been defined in law as a professional service but it sure as hell seems like one to me. Maybe if it were treated like one we could all have our cars actually repaired correctly.

Jason

dlmeyers

Hello again,

"Ghosting" is a term likely not found in electronic textbooks. Best described as jargon. Generally refers to conditions where codes are stored with no apparent reason or effect on overall operation. They may show up, cleared, never to be seen again. After about 50 ignition cycles, even the computer may dump em. Weak grounds, sensitivity to electromagnetic interference(espcially ABS), several sources for error.

Engineers develop criteria/parameters to determine when they want the code set, system deactivated, or simply alert the operator something has occured. Some must occur several times before a particular code is set. Those associated with ABS often set very quickly with little deviation allowed, like wheel speed sensors.

Still, they are computers. C4's, some are over 17 years old.

With you car running well, I would suspect some procedural fault with the test. Without knowing the test procedure, this is speculation on my part.

Would propose there is a difference between a mistake on a test procedure and a deliberate attempt to defraud. Not sure what we have here. I do know of fraud in car repairs. Many many years ago, a friend asked my Dad to repair a Cadillac transmission over a weekend. He had received a bid for this service and my Dad said he couldn't take the job, at that price, anytime, let alone on a Saturday and Sunday. Late Sunday afternoon I helped my friend pick up the car. After looking around the shop, I saw no parts boxes, no fluid stains, no old parts. Test drive by friend was good, paid by check. Still curious, drove the car to a service lift, looked at the transmission, still coated in old grease, gravel, dirt, etc. The crook merely added about 2 to 3 quarts of transmission fluid that had been leaking into the radiator. Friend stopped payment on the check. I fixed the radiator. That was fraud.

Hope things work out.

dlmeyers 90 coupe zf6 3 speed shocks

Mike_88Z51

jsaunde2,

I would guess that the Tech-2 can be configured to send signals directly to the controller to insure the controller can actively and correctly diagnose the problem as it happens on the car. Here's why.

When checking for a defective ABS controller there are 2 conditions to consider. 1) The controller reports falely that a LTPWS is nonfunctional. 2) The controller does not report a nonfunctional LTPWS when there is one. Under condition #2, if the ABS controller is defective and does not show a bad LTPWS this would put the driver and vehicle at risk. So, how do you check that the controller is acurately monitoring the LTPWS sensors when the sensors are good? You send it a false signal. If it reports a bad LTPWS when sent a false signal, you know it is working correctly and the ABS controller can be trusted.

I agree with you. Turn them in. I would start by contacting the good dealer and asking them if it is possible to cause the light to come on using a Tech-2. They obviously know how to use the tool properly. Ask someone who has already shown they know what they are doing. have them explain how they test for a bad controller that DOES NOT report nonfunctional LTPWS sensors.

Then write this incident all up in a clear letter and send a copy to the BBB ans the Texas department that investigates automotive fraud. If enough people do this they will get nailed eventually.

"All that is necessary for the triumph of evil is that good men do nothing."
- Edmund Burke

ZylaRace

I do think the mech was just plain incompitant. Least that is what I want to believe, (i.e. I wasn't there).

If you have the time and want to persue it,... go for it.
One of the pitfalls of doing business w/ any shop,.... you pay for their mistakes, unless per chance you catch them at it. That is where you come into the picture.

BTW: I disagree w/ you on the mechanic being a professional.