Hello, my 2004.5 had shuttle shift, lingering in gear, no od problems, so I dropped pan and installed new pressure solenoid and sensor. After new filter and fluid, ran truck and it fixed all issues, or so I thought.....Drive highway speed, then stopped. Upon takeoff it was starting in 3rd. So... I checked codes, still getting line pressure code and solenoid code. After checking codes, it worked perfect...until stopping after highway test. Same issue. If I stop, simply shut truck off and restart, it works perfectly at lower speeds and stopping. If I run it to Highway speeds and stop, it will do same thing and start off in third unless I manually shift it. Anyways, it started working good, but codes were still on the dash. Will they go away on their own or what? Am I supposed to clear codes after changing solenoid and sensor? I'm at a loss...

 

It is usually best to clear the codes after the repair and see if any codes come back or if new codes show up. If after your repair, the same codes come back, then you need to be looking at other things in that system that work with those components that may have failed. Usually a stored trouble code wont go away on its own and must be manually cleared. There are some that will clear themselves after a certain number of cycles w/o the failure being present but most need cleared manually.

 

The solenoid code went away, I still hadon't line pressure code, cleared it with a scanner, it worked perfectly for awhile. I got into the throttle hard and when I did that, the line pressure code came back, solenoid code remained gone. I'm not sure if the sensor I put in was actually bad out of the box or what. Should I try a backslash on trans? Getting frustrated....thank you.

 

Backflush*

 

I normally don't recommend back flushing as it usually causes more problems than it solves. You didn't say if this is a low or high pressure code.

 

I'm sorry, it is saying low pressure, I'm on the verge on ordering the BD transducer upgrade kit, but looking for input. I highly appreciate you helping me with this, I will not backflush.

 

Some have luck with a backflush, I never have. Always seems that it breaks other stuff loose and gets caught in the valvebody and just causes more problems. Is the trans making any noises like a pump whine or growl? Also i have seen some filters that just dont seal right to the case and cause problems after getting up to operating temp, just had a guy smoke a 4L60E cause the NAPA filter didnt fit correctly and would suck air after getting warmed up. How did the fluid look when you dropped the pan the first time, dark, burnt smelling, any glitter?

 

Fluid looked a bit dirty , I believe it was original with 93,002 miles on it. The pan looked clean, with just a bit of stuff on the magnet, not horrible. No large pieces whatsoever, just some fines on magnet.Fluid looked just a bit brownish, but did not smell burnt at all, nor was it glittery. No whine or growl from trans pump, nothing. It was a napa filter, solenoid and transducer. Solenoid definitely working correctly. Ive decided against back flush. Again, thank you

 

I have also heard of the issue with the filter fitment causing problems. Should probably check that. Also, don't "back flush" the system. However, you can certainly flush the system with new fluid. You won't get out the previous old fluid with just a drain/service. There are cooling lines and a bunch of things. Flushing and running clean fluid throug the system to purge out the old should be considered.