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tim's auto repair
tim's auto repair, mechanic
Category: GM
Satisfied Customers: 15465
Experience:  owns a repair shop....25 years
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Transmission issue. 2004 2500 non HD crew, 4x4, 6.0l with

Customer Question

Transmission issue. 2004 2500 non HD crew, 4x4, 6.0l with 4l80e. When cursing under 65mph the torque converter locks up fine,and run about 2300 rpm, once above 65 it will unlock and run 2500 rpm. If slowdown occurs below 55 it will lockup again until the 65mph mark. No DTCs, what should I be looking for?
Submitted: 1 month ago.
Category: GM
Expert:  tim's auto repair replied 1 month ago.

Hi, My name is ***** ***** for the delay.
I will do my best to assist you.

Expert:  tim's auto repair replied 1 month ago.

and you never get a trouble code?

Customer: replied 1 month ago.
I have had a p300, random cylinder misfire, it resettled itself. I have added New wires and plugs, I also ran a bunch of injector cleaner though it was well. That was a couple of months ago, been kinda lazy chasing this issue down as I drive my car most of the time now. I have read that a crank relearn will sometimes fix this issue. Yesterday I borrowed my mechanics snap on scanner and tried it but it didn't work as it failed on the step that requires to engine to fuel cut off. The truck didn't really bounce of the rev limiter. It hit the fuel cut off once then would just rev full throttle.
Expert:  tim's auto repair replied 1 month ago.

so,,now it has no codes at all?

Customer: replied 1 month ago.
Correct
Expert:  tim's auto repair replied 1 month ago.

does the transmission ever slip?does it ever shift like into neutral by itself then back into gear?

is the only problem the lock-up converter kicking out?

Customer: replied 1 month ago.
Never slip, fluid is clean and doesn't smell burn. It shifts well. The only issue is it unlocking about 65
Customer: replied 1 month ago.
Mph
Expert:  tim's auto repair replied 1 month ago.

ok..

i would think you have one of two possible problems here

1-the pwm solenoid or

2-the pressure switch

Expert:  tim's auto repair replied 1 month ago.

consider just replacing all the electronic solenoid and switches while you have the pan off

Expert:  tim's auto repair replied 1 month ago.

If you are satisfied with my answer, Please Rate my answer by clicking the rating button so I can get credit for my work. I’m not always going to be giving you good news, so please don't let this stand in the way of you accepting my answer. .it does not cost you more money and we will still be able to communicate, ,.please understand, i can not see, hear or touch the vehicle and only know what you tell me. Bonuses and positive feedback are appreciated.. if you are not satisfied with my answer, please do not leave bad feedback ,i will gladly opt out and let another expert handle the question. .if i have sent any diagrams, please print them. .sometimes you may need to right click the image [,then save picture as]to save it to your computer so you can open it with your picture program...Please ask if you need more help.