GM 4L60-E problems
I have this 2004 Chevy Trailblazer that will not go into gear.
The only thing I really know about the vehicle is that the last owner had said that he changed the filter and fluid, but when the vehicle was brought to me by the new owner, there was no fluid, and there were only three bolts holding the pan on. So that put me back to square one.
So I put the pan back on properly fill it with fluid in an attempt to at least get some DTCs but none related to the transmission or drivetrain.
so I went into my scan tools bi-directional controls to see if the PCM was seeing the commands, and it is.
When I put the car in drive, I see it in drive on the display; the scan tool sees that the shifter was moved, but the transmission does nothing.
I then backed probed the pins for 1-2 solenoid and 2-3 solenoid with a test light, and it lights on the 2-3 solenoid, but I get nothing on the 1-2 solenoid.
Hi Albert can you please check the fluid level with the engine off and engine running if the fluid level remains the same it tells you the pump is not picking up the fluid . Which could mean broken pump or possibly the filter is missing.
Line pressure is not necessary at this point . It is most likely a mechanical failure . The test I outlined should point you in the direction of the next test.
The solenoids will not keep gears from engaging. You need to get pressures from the port on side of trans. Are you sure it is full of fluid? As previously asked get fluid level engine on and off to see if it changes, With trans unplugged you should have reverse and forward. (2nd or 3rd gear, dont remember which) But it should move even without the solenoids working.
Unplugging the main electrical connector would default to third gear. If you still have no movement internal problems. Both shift solenoids are on for first gear.
Albert, Do you have reverse? If you do it's not a pump/fluid issue. If it doesn't did you check and make sure the filter was fully seated and not double sealed? The forward clutch if fed straight from the manual valve and even with no electronics involved you would have third gear. Try putting it in manual 1st and see if it moves. If it does this would point to a forward clutch problem. If it…
Hi Albert, I agree with the others and think the pump is broken or the convertor has shelled out and stripped the input shaft splines. The first owner sold it to the second owner this way? You are not getting the full story. (That's not uncommon)
At a minimum it should have limp home. If it is full of fluid and the filter and seal are installed pull it out. Internal issue
OK Thank you to all. I have another trailblazer that was pretty much abandoned four years ago because of frame rot which I took possession of. so I'll just swap the trans.
Great idea but you should perform a few basic tests before condemning it Albert . The problem with no movement could possibly be in the transfer case as well if it is 4 wheel drive .
It possibly could be in neutral or broken but if that happens you will get a loud grinding noise when you try to move in drive and when you put gear shifter back into park . Also of some one had pan off it’s possible they broke the manual valve clip as well which would be no movement . All I am saying the possibilities are many And should be tested to determine the cause . not just a magic bullet
Hi Albert, I just thought of another possibility… last year I had a truck come in for a no movement in any gear problem. It turned out that the axle shaft had broken due to a bad bearing overheat issue. So I recommend set the park brake and block the wheels, start the vehicle and put it in gear then look under it to see if the driveshaft is spinning.
It would be really helpful to look at the pressure PID's. Desired and actual. If you have no pressure you have no drive. You did not say if anything happens with reverse. It is totally independent of electronics. If you get reverse, the pump works and the converter is driving the input. If nothing and no pressure showing on the PIDs you are done. Pull it out…major damage is likely.
Hi, Check the seal on the filter. It has to be tight. Dien
All of the responders have given good advice. If you cut power to the transmission it should drive line pressure high and forward launch in third gear in order for the ability to drive to a workshop. (if in fact you have fluid and the filter is properly installed) If you cut power and it still doesn't move forget the electronics for now because you have a mechanical failure. You can re-visit the…