1993 2500 suburban will not shift out of 2nd

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by nutpants, Sep 22, 2009.

  1. nutpants

    nutpants New Member

    just bought a 1993 suburban 2500 310000kms last owner said they put a tranney and transfercase in 4 years ago.
    5.7L 4X4 4le80 trans
    it will not shift out of second.
    NOT that 3rd is missing
    just that it keeps going in second with the engine screaming at 80kph (50 mph)

    other problem that i have not fixed (but will when i have time) that may contribute.
    high idle ( very high) might be map sensor or other sensor.
    engine temp sensor at the front of the engine was broken off (have one ordered)
    truck sat for a year before i bought it last week

    any ideas?

  2. Tuner

    Tuner New Member

    i just fixed this problem on mine, it wasnt as bad of a problem but similar, the kick down cable that is one the throttle bodies might be to tight and you may need to loosen this up some. if your looking on the truck, its on the driver side and it has a plastic screw that has a cable lead coming through the center of it, i screwed mine in to where it has about 1/4 of an inch of play. i cant currently find a fiche online to show you the actual cable, but with what ive said, it should be easy to find.
  3. nutpants

    nutpants New Member

    is there a kick down cable on the 4le80 transmission?
    i thought the transmission was completely electronically controlled.

    i looked where you said , the spot where the kickdown cable is attached if the 700r4 transmission was there is empty. i expect the same spot would be used if this tranny (4le80) had a kickdown cable.

    thanks for the info it might be the electronic kickdown is acting up.

  4. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    There is no kick down cable on a 4L80E transmission. The shifts are controlled by the computer. Have you checked for codes yet?
  5. nutpants

    nutpants New Member

    i dont have a code reader and the shops here (small town) cant get me in for a week or so. can you get the codes for the tranny if you dont have a reader?

    ( its my first electronic transmission)
  6. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    No you must have a scanner or code reader. Call around and you may be surprised to find a shop that will scan it for you.
  7. bigburb

    bigburb Rockstar ROTM Winner 100 Posts

    I thought there was a way you could read codes with like a paperclip in the OBD port and by counting the number of flashes of something on the dashboard...?? Or has it just been too long of a week for me and I'm just imagining things?
  8. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    Yes you can jump the terminals on OBD I systems but not OBD II. The reason is OBD I codes are 2 digit which is easy to read with a voltmeter or watching the check engine light. OBD II codes are 5 digit codes which makes it impossible to read watching the check engine light. So a code reader or scanner is necessary.

    Speaking of OBD II codes:

    The first digit is always a letter and denotes the module. P codes = Powertrain codes. B codes are body codes, etc.

    The second digit is either an "O" or a "1". O = OBD Generic and 1 = Manufacturer specific codes. <OBD Generic codes are the same from manufacturer to manufacturer.

    The third digiit is a number which denotes the system. Engine, Transmission, Fuel , HVAC, etc.

    The last 2 digits are numbers which denote the code itself.
  9. nutpants

    nutpants New Member

    if the "check engine' light if off is there any way to tell if there is a fault code to be found?
    i would hate to pay the minimun shop time ( 1 hour at $90 an hour)
    just to find out there is no fault code stored to find.
  10. tm4hammer1

    tm4hammer1 Rockstar

    scanner helps

    sounds like it could be 2-3 soliniod or a shift valve is stuck ,quad driver module could have failed,but the VCM also moniters coolant temp for your torque converter clutch electrical controls i would check your connections and also voltage to the soliniod but realisticly your just going to have to pull those codes replaceing parts is a helva lot more expensive and make sure you get the read out of all the codes . as far as the high idle it is more than likely the coolant temp senser the VCM takes that reading andBATTERY VOLTAGE, ENGIAN LOAD AND rpm compares it to ambient air inlet temp and adjusts the IAC valve mounted in the throtle body accordingly If the VCM has been without power it will lose its learned idle setpoints and replace with a defalt if after you replce the coolant senser and drive for a bit with multible start-ups it does not reset itselfthen i would look for vacume leaks and pull the IAC only with the ignition off clean it and reinstall use carb cleaner and liythium grease again a code reader would be of benifit here as alot of components andsystems could be involved have the guy pull all the codes it would be worth the 90 bucks believe me in the long run on both counts and should be able to do it in well under an hour or wait till you have your coolant senser installed and everything resets never know

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