OBD2 adapter for 4L80E connection

[Dave2018]

Only have a small issue coming out of 1st gear. Need to get the readings checked out before opening up. Has anyone seen this being sold.
Thanks for all replies.

 

[Mogman]

Only have a small issue coming out of 1st gear. Need to get the readings checked out before opening up. Has anyone seen this being sold.
Thanks for all replies.

I doubt you will find much useful information available in the first gen. diesel 4L80E TCM it was very basic with a couple of analog readings (RPM) I don't think it even had a TPS or any pressure readings, at that time they relied on trouble codes almost exclusively which you do not have to have a reader to get.

The gen I diesel TCM was only used from 1991 until 1993 when they went to an ECM/TCM with the introduction of the 6.5L the gassers had been using ECMs since the mid-late 80s

But the military did not want anything to do with an ECM so they kept equipping the 6.5L with mechanical IPs and stuck with the gen I diesel TCM

EDIT, on top of the military wanting as small a list of repair parts in the "chain" as possible it probably was considered better to be able to drive out in 2nd gear in case of an EMP event than loosing the truck completely.
Of course now there are ECMs, TCMs and electronic controls all over the military.

 

[Dave2018]

I doubt you will find much useful information available in the first gen. diesel 4L80E TCM it was very basic with a couple of analog readings (RPM) I don't think it even had a TPS or any pressure readings, at that time they relied on trouble codes almost exclusively which you do not have to have a reader to get.

The gen I diesel TCM was only used from 1991 until 1993 when they went to an ECM/TCM with the introduction of the 6.5L the gassers had been using ECMs since the mid-late 80s

But the military did not want anything to do with an ECM so they kept equipping the 6.5L with mechanical IPs and stuck with the gen I diesel TCM

EDIT, on top of the military wanting as small a list of repair parts in the "chain" as possible it probably was considered better to be able to drive out in 2nd gear in case of an EMP event than loosing the truck completely.
Of course now there are ECMs, TCMs and electronic controls all over the military.

Thanks for this info. I have a 2007 M1152A1. Low miles. Maybe I could just put in a new 1-2 solenoid valve. And not try the connector after all. It shifts out of 1st but takes a little too long.

 

[Mogman]

Thanks for this info. I have a 2007 M1152A1. Low miles. Maybe I could just put in a new 1-2 solenoid valve. And not try the connector after all. It shifts out of 1st but takes a little too long.

Have you checked to see if it has any codes? not all codes cause a trans light

 

[Mogman]

Also put a pressure gauge on it and see if there is a pressure drop in 2nd, if it was the A solenoid (1-2 shift) it would likely act up in 4th when fully warmed up.
There of course will be a pressure drop during the shift but it should recover to about the same pressure as 1st.
Otherwise it could be a 2nd gear clutch pack, but it would be much easier to try a new A solenoid first.

 

[Dave2018]

Woof....something may be going on that I'm not aware of. Done tons of mechanical but never transmissions.

If it doesn't smooth out could buy the Delco solenoid and wiring kit. That's something I should be able to do.
Hope with less than 1200 miles it will free up after good fluid flow at temp.
Thanks
D.K.