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Thread: TPS Fault codes and cams

  1. #1
    Forum tyhee Site Admin GMPX's Avatar
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    Default TPS Fault codes and cams

    WOW, the first how to and the winner is a simple DTC fix.

    O.K, so anyone who has fitted a cam knows the dredded TPS fault code that comes up (usually P0121 at idle with the A/C going).

    Instead of simply turning off the fault code in the DTC enabler section, all that needs doing is to 'expand' the range the PCM thinks is a valid Throttle Position.

    Look at table - C3907
    It's pretty simple how it works.

    For a given RPM the PCM expects the TPS to be above a certain percentage. Looking at the attached screen shot...

    At 400 RPM, the PCM expects the TPS to be at 0%.
    At 800 RPM, the PCM expects the TPS to be at 1% or higher.
    At 1200RPM, the PCM expects the TPS to be at 5.3% or higher and so on.

    Now, throw a camshaft in that needs to idle at 850, 950RPM and the PCM is still going to expect the TPS to be at 1% or higher.....not the case with your new cammed motor.
    So, just simply identify your idle speed range, and change the values to 0 so the PCM will now accept the throttle is allowed to be closed at 950RPM.


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    GMPX Hi!
    I was curious why mine never set. Checked my orig file - 0121 is turned off from ht e factory. Starndard for ETC??
    Cheers,
    joel

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    Forum tyhee Site Admin GMPX's Avatar
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    Quote Originally Posted by bink
    GMPX Hi!
    I was curious why mine never set. Checked my orig file - 0121 is turned off from ht e factory. Starndard for ETC??
    Cheers,
    joel
    What year is your car?
    I just checked some 2000 and 2001 C5 files and they both have that DTC test enabled. Maybe Chevy knew what was going to happen to your car.

    Cheers,
    Ross

  4. #4
    Lifetime Member jfpilla's Avatar
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    Quote Originally Posted by GMPX
    Quote Originally Posted by bink
    GMPX Hi!
    I was curious why mine never set. Checked my orig file - 0121 is turned off from ht e factory. Starndard for ETC??
    Cheers,
    joel
    What year is your car?
    I just checked some 2000 and 2001 C5 files and they both have that DTC test enabled. Maybe Chevy knew what was going to happen to your car.

    Cheers,
    Ross
    Mines an 03' and it's also off?
    2003 red vert
    Mods:
    LS7 crate engine, wet sump, 24xx reluctor
    LPE 100mm MAF
    Vararam, cold air intake and bridge
    RPM Level 6/4L60e trans
    3.42 gears
    Yank SS3600
    1-7/8" AR headers
    Z06 exhaust
    470rwhp 437rwtq
    1/8th mi-1.526-60'-6.862-1/8th-@100.74mph

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    Quote Originally Posted by GMPX
    What year is your car?
    I just checked some 2000 and 2001 C5 files and they both have that DTC test enabled. Maybe Chevy knew what was going to happen to your car.

    Cheers,
    Ross
    My car is a 2001. I think it's special.



    What do you mean maybe Chevy knew what was going to happen to my car?!!

    Where is the "Face hurts laughing " emoticon??

  6. #6
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    Quote Originally Posted by GMPX
    What year is your car?
    I just checked some 2000 and 2001 C5 files and they both have that DTC test enabled. Maybe Chevy knew what was going to happen to your car.

    Cheers,
    Ross
    My car is a 2001. I think it's special.



    What do you mean maybe Chevy knew what was going to happen to my car?!!

    Where is the "Face hurts laughing " emoticon??

  7. #7
    Forum tyhee Site Admin GMPX's Avatar
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    Do all you guys have Z06's?, I just looked at a stock Z06 file and it is turned off.

    Bink, I just meant, you would be messing with the car at some stage so Chevy saved you the trouble.

    Cheers,
    Ross

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    Mine's a Z06.

    Bink, I just meant, you would be messing with the car at some stage so Chevy saved you the trouble.
    Yeah, I knew..... just a retort. Your comment was why I was looking for the "Face Hurting Laughing" emoticon.

  9. #9
    Lifetime Member jfpilla's Avatar
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    Quote Originally Posted by bink
    Mine's a Z06.

    Bink, I just meant, you would be messing with the car at some stage so Chevy saved you the trouble.
    Yeah, I knew..... just a retort. Your comment was why I was looking for the "Face Hurting Laughing" emoticon.
    Joel,
    Did you get my mail?
    Your just too subtle. :lol:
    2003 red vert
    Mods:
    LS7 crate engine, wet sump, 24xx reluctor
    LPE 100mm MAF
    Vararam, cold air intake and bridge
    RPM Level 6/4L60e trans
    3.42 gears
    Yank SS3600
    1-7/8" AR headers
    Z06 exhaust
    470rwhp 437rwtq
    1/8th mi-1.526-60'-6.862-1/8th-@100.74mph

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