1997 Silverado Z71 tranny problems.

Discussion in 'Chevy Truck Forum' started by Z97_Silverado, Jan 15, 2010.

  1. Z97_Silverado

    Z97_Silverado Full Member

    Joined:
    Dec 13, 2009
    Messages:
    46
    Likes Received:
    2
    Hi all, I am a newbie here and I am looking for some info as to what can cause my tranny to act the way it is.

    Just so you know I bought this truck (1997 Chevrolet Silverado Z71 4x4)this a few weeks ago with this problem but was told that it needed a new neutral safty switch as that is the cause of the problem. Now to my knowledge all that switch is supposed to do is prevent starting in gear but my dealership told me that it does about 18 different things but wouldn't enlighten me as to what those things are.

    My truck will not shift unless I do it manually, also my speedo and tach will not function at all but the other gauges on the cluster do except my gear indicator light and my check engine light is always on.

    I have checked the codes and they come up as the following and the meaning that my code reader gave for each code:

    CODE
    P 0740>>> Torque Converter Clutch Circuit Malfunction
    P 0753>>> Shift Selonoid A....Electrical
    P 0758>>> Shift Selonoid B....Electrical
    P 0785>>> Shift/Timing Selonoid Malfunction
    P 1860>>> Dealer Specific....TCC Solenoid Circiut (thats what the dealer told me it meant)

    Now I have been searching throught alot of posts on here and have came across a few users posts (mudseeker for one) that all seem to point to the problem being the Ignition switch, so I ordered one up and installed it today. I was very excited when I finished the install and was about to start her up for the first time and well my excitement quickly turned to WTF mode as nothing was different at all when I started it up and sat for a few minutes, engine light came back on and i got the same codes.

    I mentioned the Neutral safty switch earlier and just to clarify....I HAVE NOT installed it yet as I dont think that has anything to do with the issues I am having(but I've been wrong b4).

    I dont regret following the info on here that I read as it all made sense and it cured alot of peoples problems in the past.....just not mine lol. So I guess I am looking for some more info or some other suggestions as to what the problem might be or other things to check out.

    Sorry for the long post and I hope I have been informitive enough to get a few responses.....lord knows I need em lol

    Thanks
    Mike
     
  2. Kennyray

    Kennyray Moderator Staff Member

    Joined:
    Oct 6, 2005
    Messages:
    1,848
    Likes Received:
    2,087
    You need a scanner to clear the codes, then you will find out if you fixed the problem.
     
  3. Z97_Silverado

    Z97_Silverado Full Member

    Joined:
    Dec 13, 2009
    Messages:
    46
    Likes Received:
    2

    I cleared them, again after your message and it came back with

    P0740
    p0785
    P1860

    And the others were gon for the time being and the tach and speedo still had nothing
     
  4. Kennyray

    Kennyray Moderator Staff Member

    Joined:
    Oct 6, 2005
    Messages:
    1,848
    Likes Received:
    2,087
    You may have to replace the switch on the tranny, I believe it would be the VSS, Hot Rod would know more. Send him a PM to get his attention
     
  5. mudseeker

    mudseeker Senior Member

    Joined:
    Feb 2, 2006
    Messages:
    8,717
    Likes Received:
    513
  6. Z97_Silverado

    Z97_Silverado Full Member

    Joined:
    Dec 13, 2009
    Messages:
    46
    Likes Received:
    2
    just goin to get the volt meter and check the tranny 20 fuse, brb
     
  7. hotrodpc

    hotrodpc Senior Member

    Joined:
    Jul 29, 2008
    Messages:
    7,277
    Likes Received:
    108
    I say the ignition switch was a very good suggestion and a bit suprised myself it did not correct your problem. I got your message Z97. BTW, welcome to the forum. Keep in mind there are 2 requirements to be a member here. It used to be only 1, but I make up rules as I go and it sounds good, so everyone else take note too. #1, must have pics of your truck in your album. #2 you must post back what repaired your problem, and keep us updated on what you have and have not done. So far you are on top of #2, and a good detailed post to start with too, lengthy or not, sometimes its required. Gimme just a bit of time here to do a bit of research and see if this can not be related to the VSS (Vehicle Speed Sensor) or a PCM (Powertrain Control Module) if your vehicle even has one. I am leaning toward VSS because the ignition did not fix your problem and all the codes you have are related to the transmission, shifting, converter locking up etc. The codes you have can not function without being told what to do. So, have to figure out who is boss and supposed to be telling these things what to do and that should solve your problem. I am a bit suprised there is not code for the VSS though, so that may not be the problem either. And I am not going to rule out the P N safety switch either, because it does do many things if you have the one thats on the outside of the transmission case. I'll take a look at a few things and post back.
     
  8. Z97_Silverado

    Z97_Silverado Full Member

    Joined:
    Dec 13, 2009
    Messages:
    46
    Likes Received:
    2
    ty 4 the welcome

    please excuse the way my message looks as my wife is on the pc and im trying to reply using my ps3 lol

    i have a n s switch here but i have not installed it yet, i dont think my vss is the likely culpret either, i forgot to mention that even tho my speedo doesnt work,my cruise control still does.

    also, my truck pick will b up soon, i just gotta find that **** cord for the camera lol
     
  9. hotrodpc

    hotrodpc Senior Member

    Joined:
    Jul 29, 2008
    Messages:
    7,277
    Likes Received:
    108
    So, I must be on the right track. EVERYTHING I am reading says its the ignition switch. I found one other info source. It said to replace with a good known PCM unit. If that does not correct the problem, then test VSS and TPS. Not likely you have a PCM laying around, so it might be a good idea to just start with a test of the VSS and see what you got. Also, you are sure the big connecter to the igniton switch is plugged in real good? Maybe try to unplug it and reseat it. Problem really should have been the switch. The codes you have fit the problem to a T.
     
  10. Z97_Silverado

    Z97_Silverado Full Member

    Joined:
    Dec 13, 2009
    Messages:
    46
    Likes Received:
    2
    i do believe that it is in there snug as 2 fat chicks in a 51 merc lmao, sorry. Anyways i will have to go out again tommorow and check it, when i picked up my volt meter my batteries were dead cuz my buddy left it on for like 2weeks haha.

    I still dont know about the vss or the "TPS"? Throttle positioning sensor? lol i think thats what that stands for correct me if im wrong, tommorow i am going to replace the n s switch and see what that does, if it does nothing then i will try to trace the wires from the tranny up.

    I agree tho, the codes that are showing up and everything I have read on here does seem to point to the switch tho. Does my truck need to b reprogrammed or anything after the switch install?
     

Share This Page