Hi Maybe someone can help me. Truck 99 Silverado. Turbo 6.0 on P59. 4l80e. HD2 Yank pro truck Transmission been in truck 5yrs has low mileage Quicksilver shifter. Tuned on HP tuner.
Crank up truck warm up shift into reverse no problem to gift to drive nothing and gear indicator lights up 2nd gear. Acts like in neutral . Shift to any gear light stay on 2nd gear. Shift to park and back no reverse or any other gear. Have to shut the truck off, crank up and can only get reverse. NO codes NO codes..
I replaced Both VSS sensor as info I found stated light 2nd gear is Limp mode. When I did change both sensor. All gears work from Park to 1st one time move out of 1st right back to 2nd truck has no power to wheels. Tranny has worked perfect for years has really not been Driven much.
I can’t keep buy parts hoping to hit jackpot… Hope my wrote up make sense. lol. Thanks

 

Have you dropped the pan for any indication of clutch material or debris?

Or maybe start by checking fluid level. Next step can be hooking up a line pressure gauge. There's a thread plug behind the NSS although it's kinda difficult to hook up a hose. Third step may be dropping the pan, depending on what you get for the line pressure.

 

No I haven’t drop pan. As I really think it’s electric. I have debut reinstall map on ECM with HP tuner but last time tuning we didnot save file to my computer, I’m not sure if copying it now and reinstalling will just be me install problem again on ECM. Hope that made sense.

 

Check for 12V on Pin E at the 20 pin connector with the ignition on.

Your first post wasnt too clear. The trans has been fine for 5 years then all of a sudden its not moving?

IF it has power with ignition on i would use the scanner to cycle the solenoids to see if they are working. You can hear them from the pan.
If they are working then i would put a pressure gauge on it to see what pressure is doing.
You could have broken the forward sprag resulting in no forward gears.

 

RDF1. Try again. Cranks up will drop into Reverse very time but it’s hit or miss ( most miss) about going into drive , if identical going into drive the indicator light will show 2nd then you can move shifter anywhere and it like in neutral, indicator stay on 2nd till pull back park then turn key off . Start all over again.. census nonsense started i changed both VSS sensor and tranny act perfect from R to N To 3 to 2 to 1 but when I whine back up to 2nd lose power to wheels Indicator light stayed on 2nd..
the tranny has been flawless.
Tranny has less then 100 miles after installing turbo. 4 yrs ago Tranny had 60k when I got it has HD2 kit YANK Stall 40k cooler did 1000miles before turbo. It’s been 1 thing after another. Was blown head gasket bad tune . Hot side SS manifold warped. Plus I have other project too.

 

RDF1
I’m going to check pins like you mention in few days. I wish I knew HP tuner as I have it & laptop. Want to reinstall map but we tuned it on my tuners laptop don’t save to my laptop at time. . I worry copying map to my laptop will only copy a possible problem with the map in the ECU.