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My TA is stuck in open loop

This is a discussion on My TA is stuck in open loop within the General Help forums, part of the LSx Technical Help Section category; I can't get the car into closed loop. What I understand it only needs to meet a couple perameters to ...

  1. #1
    Junior Member blackonblackws6's Avatar
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    Unhappy My TA is stuck in open loop

    I can't get the car into closed loop. What I understand it only needs to meet a couple perameters to do so, the engine temp is at 180*, the O2's have varying voltage, they are getting hot, they are new, zero miles! There are no DTC's. when i'm driving it flashes from open/closed and stays open at idle or not moving. I put the car on stands and as soon as the drive line starts to move it will read closed then open, goes to open when it comes to a stop. I think I checked every thing but obviously I'm missing something. any ideas? what other variables does the PCM want to go to closed loop. I replaced the O2's hoping it would solve the problem, nope. I changed MAF, ECT, MAP could some other sensor be reading bad info and not letting it close? Am I in the twilight Zone? The car seems to run great, i noticed this on the scanner when I was looking for some thing else. The mods are; wrapped long tube headers, air lid, SLP 85mm MAF, no cats with sims, ORY pipe then I had the cats O2's programmed out and the rear end ratio changed. thats the only ECM mod done but it was doing this before before, I just wanted the sims out of the picture. 2002 WS6 TA LS1/A4
    I really need some help, the GM stealerships all suck around me and I've tried talking to everyone I know who knows anything about this stuff.
    thanks for any help you people can offer.
    -MP
    Last edited by blackonblackws6; 01-11-2009 at 07:00 PM.

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    old timer blue02Z's Avatar
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    first get rid of the slp maf

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    Junior Member blackonblackws6's Avatar
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    Quote Originally Posted by blue02Z View Post
    first get rid of the slp maf
    why? it has run great for a few years with it until this issue. I've got a cam / heads FAST intake and TB and a NO2 kit waiting in the shop to put on it but want to fix this issue first. you're saying spend the money for the stock MAF and bellows (thats smaller) because thats causing the problem or because some people have had other tuning issues? The SLP is supposed to be calibrated for this year model LS1 F-body. I'm confused

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    Veteran 0rion's Avatar
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    Quote Originally Posted by blackonblackws6 View Post
    why? it has run great for a few years with it until this issue. I've got a cam / heads FAST intake and TB and a NO2 kit waiting in the shop to put on it but want to fix this issue first. you're saying spend the money for the stock MAF and bellows (thats smaller) because thats causing the problem or because some people have had other tuning issues? The SLP is supposed to be calibrated for this year model LS1 F-body. I'm confused
    is there anyone local with a stock maf that you can borrow and throw on there to test? The aftermarket MAF's are headaches most of the time...calibrated or not. If you tune for it they can be fine but they're usually not just plug and play. I'm not saying run out and spend money on a maf just yet but I sure would want to run a stock one to see if your problem goes away......I bet it would.

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    Veteran 0rion's Avatar
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    I remember someone else having this same problem but I'm having trouble remembering the fix. Let me dig around and see if I can find it.

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    Veteran 0rion's Avatar
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    have you first checked your wiring to the O2's and made sure your headers haven't burned any of it? It sounds like you're using a scanner correct? What scanner and are your O2's sticking at 450mv for any amount of time?

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    TunedbyFrost.com Tuner Frost's Avatar
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    How are you determining OL? Are you looking at a status bit or actual operation? Have you verified that STFTs are at 0 when you believe the car is in OL? Once the PCM sets a code that forces OL, it should remain in OL until the code is cleared or the vehicle is restarted.

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    Junior Member blackonblackws6's Avatar
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    Quote Originally Posted by Frost View Post
    How are you determining OL? Are you looking at a status bit or actual operation? Have you verified that STFTs are at 0 when you believe the car is in OL? Once the PCM sets a code that forces OL, it should remain in OL until the code is cleared or the vehicle is restarted.
    Snap on scanner; live data screen says open loop and says there until i put in drive and start to move the wheels. then it will flash open then closed in no certain pattern until the wheels stop it reads open again. there are NO codes in history. the O2 readings start out around 900's at first when cold then vary around 600's. they a brand new yesterday. i'm gonna try a stock MAF from my buddy today. let you know. no burnt wires for O2's. thanks guys your all great.

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    Veteran 0rion's Avatar
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    Quote Originally Posted by blackonblackws6 View Post
    Snap on scanner; live data screen says open loop and says there until i put in drive and start to move the wheels. then it will flash open then closed in no certain pattern until the wheels stop it reads open again. there are NO codes in history. the O2 readings start out around 900's at first when cold then vary around 600's. they a brand new yesterday. i'm gonna try a stock MAF from my buddy today. let you know. no burnt wires for O2's. thanks guys your all great.
    next time you log it log short term fuel trims like Frost said and see if they're zero'd out when it's saying open loop. Are there any drivability issues with the car?

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    Junior Member blackonblackws6's Avatar
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    Quote Originally Posted by 0rion View Post
    next time you log it log short term fuel trims like Frost said and see if they're zero'd out when it's saying open loop. Are there any drivability issues with the car?
    no drivabilty issues, it seems to run great, no stalling, smooth idle. does smell a bit rich but i guess that would be expected with open loop headers ect. and the air here is cold right now but it was doing this when it was 70*. stft are not stuck @ dead zero, vary between -1.6 and 1.0. the stock MAF did nothing for it, just tried it and let it get hot 178* ish on scanner. It was a loner, probly wasn't from the exact year model car. I can go to the salvage yard and try to get a used one cheap enough to test it out if you thinks its still a good idea. I will get the car dyno tuned after all the rest of the mods go on, i just want to solve this issue first so it goes into PE mode.
    thanks again
    -MP

  11. #11
    That guy thearborbarber's Avatar
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    your car is going into closed loop indicated by the STFT activity. You won't have any STFT activity in open loop, they will remain zero.

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    Junior Member blackonblackws6's Avatar
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    Quote Originally Posted by thearborbarber View Post
    your car is going into closed loop indicated by the STFT activity. You won't have any STFT activity in open loop, they will remain zero.
    so... what you're saying is the scan to is f-ing up and saying open and it truely isn't. I maybe chasing my ass for no reason? wierder things have happened I guess. I will be trying a new scanner tonight, nothing worse than a broke tool. Let you all Know.
    thanks again.

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    That guy thearborbarber's Avatar
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    Quote Originally Posted by blackonblackws6 View Post
    so... what you're saying is the scan to is f-ing up and saying open and it truely isn't. I maybe chasing my ass for no reason? wierder things have happened I guess. I will be trying a new scanner tonight, nothing worse than a broke tool. Let you all Know.
    thanks again.
    Correct.

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    TunedbyFrost.com Tuner Frost's Avatar
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    Quote Originally Posted by blackonblackws6 View Post
    ....stft are not stuck @ dead zero, vary between -1.6 and 1.0. .....

    Then you are NOT in OL regardless of what the scanner says.

    Sounds like a lot of worrying about nothing; which isn't a bad thing at all

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    Junior Member blackonblackws6's Avatar
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    Quote Originally Posted by Frost View Post
    Then you are NOT in OL regardless of what the scanner says.

    Sounds like a lot of worrying about nothing; which isn't a bad thing at all
    thanks again, I will use my buddies new scanner tonight and reply. I hope you all didn't think I'm nuts, I had to think something was going on, broke car or broke scanner. OMG!

  16. #16
    Junior Member blackonblackws6's Avatar
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    I got a new scan/data tool and shazam! The engine goes into closed loop as you all said it was; indicated by the STFT. I geuss I should have known that but I couldn't believe this high dollar Snap On scanner was F'd. (they'll be getting it back).
    Thanks for the help/support on this problem, this forum has been great!

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    War Machine BIG GUNS's Avatar
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    I learned quite a bit just by reading it. Thanks.

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    That is sucky and awesome...all at the same time. False indications can waste loads of time, but it sure is nice finding that nothing is wrong!

  19. #19
    Junior Member blackonblackws6's Avatar
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    Quote Originally Posted by BowTied View Post
    That is sucky and awesome...all at the same time. False indications can waste loads of time, but it sure is nice finding that nothing is wrong!
    This this experience only proves the old saying; don't believe what you hear and only half of what you see. (The guys here did give good info) I have had no issues with the SLP 85mm MAF, FYI. I am almost ashamed to admit that I removed my 90/90 intake,tb my cam, 85mm MAF and bought new O2's before I figured out my $1000 scanner was a P.O.S. Got a new scan/data tool. All though it didn't have a problem going to closed loop / PE mode, it still didn't idle or restart worth a damn with the new cam. I fought the tuning for weeks (newbe tuner) I'll get the cam back in and start over.Then I'll be asking more questions At least this car is a hobby and not a every day nightmare job.

  20. #20
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    The cam and the intake hurts a little.

    I got my big meter indication lesson in the Air Force. Me and another guy wasted a whole shift tearing apart the aircraft looking for an high impedance wire. When we finally metered forward and backward from where we had opened the system (2 non-inclusive runs of wire) we had 2 high impedance readings. (Ohm meter would read, at least close, near 0. Must have been about 50 times higher with more than an Ohm or so.)

    Then the next shift got to put the aircraft back together. The problem was a recessed pin in the plug....we were just checking that wire, before buttoning everything up!
    Last edited by BowTied; 01-14-2009 at 08:48 AM.

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