What are the possible causes of a 4l80e to only have 2nd gear when the gear selector is in D?

 

It's in limp mode most likely, I can't tell you why but If you do a internet search for "4l80E Limp Mode" You should find plenty of possible answers.

 

Any updates to all the other problems you've had?

https://ls1tech.com/forums/automatic...limp-mode.html

Like how did you get from the end of the last post to this problem in this thread?

Heres another dead end thread.
https://ls1tech.com/forums/pcm-diagn...no-speedo.html

I don't see how something can give so many problems, it almost seems like it's not really happening.

 

The speedo issue is relevant to the 60e, no longer relevant since it's not in the truck.

4l80 issue is relevant/current.

Trust me, I want to burn this fkn thing down to the ground right now.

Thanks for the help again.

 

Bad shift solenoids, grounds, fuse blown, loss of pressure, tps, vss, wiring. All could be a problem. Its in limp mode. Only 2nd and reverse.

 

You need a technician on the case! Bring it to me....I'll fix it!

You have a GMT800 & a P59 PCM.....It can't possibly be that bad!

 

 

Thanks.

I did a complete electronic change out yesterday. No change.

I mean everything. Harness, pressure manifold switch and all solenoids.

It's in the trans somewhere or I messed up the HD2....somehow.

 

You can shift it through all the gears with no vehicle connection.
Need instructions?

Maybe Clinebarger will help LMFAO.

 

Not sure what you mean.

The 80e is in the truck. I can drive it but it only has 2nd and R.

I'm 99.9% confident that I didn't mess up the HD2 but there is that .1%.

With that being said, any other quantifiable answers to my question?

 

Transmission DTC's?

What are the Shift Solenoid states (On/Off) Engine running shifter in D4? You may have to find the correct PID's in HPTuners & they aren't always labeled correctly.

What position/state is the Pressure Switch Manifold in? D4 would be.....
A....Off
B....On
C....On

Commanded Gear?

Did you ever test out the OSS circuit like we discussed in the other thread?
Did you make sure you have a OSS Relutor on the Output Carrier?

Are you still trying to make your Flex Fuel OS work?

Attachment 718034

 

Fluid leaking into the connector will not cause issues as ATF does not conduct electricity.

 

 

Well.

I'm updating this to let everyone know about my saga and to also come clean.....I fucked when I did the swap.

I pinched the harness at the top of the bellhousing. Guess which wires were pinched?

Speedo wires and the pink 12v wire. Once I cleaned up the wires, I keyed on and verified 12v on pin E at the connector.

 

Congrats man, at least you found the problem. You must have forced the transmission to mate up with the block. I nearly did something similar a few weeks ago, kept fight tranny.... then seen the wires.