Service stabilitrack

nickb2

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#16
Most often, you will find specific codes relating to a module in bus line failure with X or Y module.

You mostly see this abundantly with germans. But VERY common on GM's nowdays. Anything will light the trac light, make it flash etc. And no amount of reflashing the modules with updated software will help when chasing a bad connection, bad ground or voltage drop across can and bus line. Especially now with mutiplex and soon optics.
 

nickb2

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#17
Case study. Yesterday. Buick lacrosse, with HUD, full auto climate etc. The awd 3.6l GDI. :eek:

Codes coming out if its arse. Which ones are real and which ones are fake. BCM codes, Chassis codes, power train codes.

Car is in reduced power mode, VCS, trac, abs and check engine lights are on.

Codes that I think are reducing power and lighting stabilitrac are addressed first. ALL flow charts tell me to address first the pcm codes then proceed to trac codes.

I fix the engine reduced situation. Clear ALL codes and test drive. Dash and engine purr. No lights. Trac and abs work fine and do not light up or come back in code fashion.

The engineers do this to "help" prevent cat failure and other possible engine management/eco friendly systems. So when certain engine parameters are not met by the pre programed algorythm, they will disable the chassis control functions as they can no longer rely on "normal" PID data and revert to a "limp in mode"
 

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#18
Hmmm. Ok, that makes sense. Sometimes engineering makes sense, sometimes not. (Not as in my thread about "Are you kidding" having-to-take-off-the-engine-mount-to-change-a-belt thread).

I miss my 01 Lesabre...one of the best engineered cars I've ever owned. Sold it three years ago to a neighbor for his kid, had just turned over 200K. Some rust, but tip-top mechanically. Per the parent, I don't think the kid has changed the oil more than once or twice in that three years. Still running by all reports.

We call it "Brad", after the commercial:
 
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nickb2

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#19
I did not relate the lacrosse story to it's conclusion. The high fuel pressure regulator/pump/sensor (685$:eek:) seemed to me to be the culprit.

History of the car shows we changed a bank 2 cat 1 yr ago. Cause of swap was a cracked flange.

Now she came back with abs and trac etc lights on. Only code that came back this time was a cat bank 2 efficiency code. And a u code with loss of communication with x modules. That is a pre designed flaw. Like I said before, "limp in". So when the pcm sees imminent cat failure, it shut down communication to all other modules that need all monitors to work. This forces the driver to actually pay attention to what the car is doing. I worte flaw before. I don't think it is a flaw, but very well thought out of on a company mindset.

So this is a type "A" code which is very high in the algorithm hierarchy. I was amazed at when I saw hex code and GPS telemetry auto correcting itself via satellite. That is one heck of a leap from a hand crank ford "T".

In regards to your daughters car and the BRAD comercial, You actually call it BRAD? That is hilarious and goes to show that you are a good dad. Women in general just have a disregard for mechanical things and just expect them to work or NOT. It's like an on off switch for them.

For a husband/BF/dad/grand dad, it is very important for us mechanically inclined vertebrae of this world to be very patient with the uninitiated. If not, you end up like this guy while his wife chomps on popcorn and laughs that peculiar know it all laugh.

 

nickb2

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#20
Case of fact you inspired me on, since it is the festivals season.

I have been going through personal stuff lately. But life does goes on. And mentors here, in their own right will steer you in the right direction IF you ask the right questions.
 

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#24
Actually, the LeSabre was my dad's car which I inherited, drove for a long time then let my boys drive when they were in college. When they graduated, I got it back and sold it to a neighbor for his son to drive. Started calling it "Brad" when I asked about how it was holding up, about 6 months after I sold it to him. Still going strong. His son is in town for Christmas, maybe I'll go visit Brad.

If I could find a rust-free LeSabre with low miles, I'd buy it in a heartbeat.
 

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#26
Dittos.

Update: Brad is reported to be "tired, very tired". Might be the end for Brad.
 

nickb2

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#27
Something I forgot to write before and trying to correct that. Often, when a car needs to cut injection due to trac. Because alot of cars cut fuel. Nowdays, they are more and more like what I will write below.

My first experience with this was way back when the new nissan 370x or Z or something to that effect came out. I went for a test drive of this supposedly fast car. Tried to dump it and have fun. Not going to happen. See trac light flashing and the damn thing cut fuel. So no tire spinning happening, very un happy with how nissan designed the limiter. I even told the client, if that was my car, I would be asking for a refund.

This was my first revelation that all these systems rely on each other.

Billr is actually better at this than I am. But I will still try to answer your initial question better than before if I can. Cuz for some reason, I know this is not a single hit thread and we will be hearing more and more about why this happens.

The reason why I say Billr or others are better at this than I am, is they have way better command of english and have had higher schooling. SO evidently, I have a hard time sounding logical. Especially when I post stupid videos. But that is my fault.

So, to prove to other co workers and such, I plugged the scanner to see what pid data was saying at time of nissans limiting. You could actually see the PCM shorting out the injectors. This is designed.

Not a very enjoyable ride when you used to spark cut off. Not the same feel to the car.

Going back to the case study of the lacrosse. Lady was not happy. She just invested 685$ for a GDI pump. I installed. It fixed most of her issues. But it had burned a cat. Thats when the readiness monitors kicked in. Here mode 6 is valuable.

Since the car came in initially with a reduced power message, first thing to do was to record all the freeze frames. Just by clearing all the codes which is an option of a high end scanner. My scanner has an quick erase option. Can copy paste freeze frames. The reduced power message went away, engine kicked to life. Now I had to use freeze frames to recreate scenario.

Only logical conclusion, cooked cat. Now try to explain that to a women in layman terms her abs light and trac lights are on due to a cooked cat we replaced a year earlier. She was saying how in the f do my brakes have anything to do with the engine? Very good question. Hard to answer.

And this is what I am trying to answer now. PCM is trying it's hardest to reboot, reset monitors. We drove the car for more than 40 or 50 klics. Ran great. Felt comfortable giving back the keys to client. Nope, she came back within an hour. 2 kids in tow. I felt very bad for her.

So I go back into freeze frames and look at what she was doing at time it coded. The car was floored at one point. Probably trying to get somewhere with two screaming kids and not really paying attention.

Funny thing here is, she actually asked me how do I know all this? I simply said cuz my scanner can read all the events. She asked me if I could read GPS locations. I said nope, my name is not Magnum PI.

Maybe she is cheating. If not, most ppl don't ask stupid questions like that. :giveup:

Anyway, at moment of abs and trac event, catalytic convertor readiness monitor was trying to pass. It did not, and I could see wheel spin of the car. At same moment engine was deciding if it would pass emissions, she floored it. This was a false negative sending this car into a toyota echo mode with crank windows.

Reason why we drove the car for 40 or 50 was to make sure the software up grade which was just insurance worked. It did not. Cuz when you do a software up grade, you need to do a drive cycle. Adaptations need to be done.

I was not the one doing the drive cycle. It did not complete. But it did complete when she got key, car and just basically did what every mom does. How was I to fault her, except for the GPS question.
 

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#30
Turns out I didn't get a chance to visit with Brad, but it sounds like he's ready to be retired. :(