JimS

Just got the truck started for the first time with the new trans after having blown up the 4l60e and replaced it with a new Extreme Street 4l80e Coan trans and 3200 converter, with the Nelson Adaptor and a new tune to convert the compouter frm a 4l60e to the 4l80e.

No matter which forward gear I put the gear selector in, the trans starts in second gear and does not change gears. It stays in second.

I have no idea if it's the trans or the computer program. Any suggestions?

My trans guy is out of town until next week. I'm just trying to get some idea where to start in diagnosing the problem.

Thanks, Jim

thunder550

iTrader: (70)

If I remember correctly that's what happens when the tune still has a 4L60E tranny segment in it.

FLT

iTrader: (1)

2nd gear is a limp mode condition for the 4l80e. Sounds like a tune or power to the trans issue if I had to guess. Vince

Wilde Racing

iTrader: (26)

If no voltage is supplied to the shift soleniods, the trans stays in second....
Check the pins in the adapter, I've had them push back into the housing insted of making contact when pluged in...

JimS

If this is the case what is the next step? Does the adapter have to be replaced or can this condition be remedied?

JimS

Thanks Vince. I called you guys first but didn't want to wait. Kind of wish I'd waited.

JimS

I'm thinking maybe I should have a pcm with my engine tune and a new 4l80e tune overnighted to me and while that's being done check the adapter pins etc.

Thanks for your help!!

Wilde Racing

iTrader: (26)

If the pins are moving, you will have to take the back of the plug apart and push them back in. The housing has a plastic tab that locks the pin in place.

JimS

It appears that the problem will soon be fixed.

The computer was throwing two codes just as soon as the truck was started, prior to moving the shift lever. Those codes were 740 and 785.

The 740 is the torque converter cluth enable selonoid circuit and the 785 is the 3 to 2 shift selonoid circut malfunction.

The computer was looking for these two items in the transmission and, I'm told, that while these items are present in the 4l60e they are not present in the 4l80e.

This means that there were segments of the 4l60e tune in the computer and this was causing the truck to run in the limp mode (thank you Vince).

A new computer is coming... overnight I hope.

I'll post up when it's running right. Thanks Jim

nonnieselman

iTrader: (10)

You have to use a Tune that already has the 4L80E in it.. and swap your Engine Segment over to it..

And if you really wanted to, you could remove the "Adapter" and swap the Brown and White wires on the Stock Harness. Then plug it back in.. VOLA...

But glad you have it figured out..