Transmission not shifting

[Chevorllac myhoe]

I have a 02 Escalade out the blue the trans seemed like it shifts from first to 3rd an that’s it No grinding slipping whining or anything before that also when you plug the obd2 in it gets power by not reading codes I hear lighter is on the same fuse I changed fuse again it has power just not reading any suggestions if not it’s going in the shop

 

[SnowDrifter]

Could you provide more info on the vehicle? Mileage, motor, service habits, driving style, in particular. Won't change the diagnostic tree, but is helpful info regardless.

IIRC there's more than 1 12v outlet fuse. Been a while since I looked in the electrical bits box

Grab yourself a DMM and verify you're getting power to the 12v pin as a first check




As far as the transmission: 3 things to check

1. How's fluid level and condition?

2. Are you able to manually shift it to second?

3. Do you have 4th gear?

 

[PNWYukon]

If it has high miles, but not slipping, I would go after the valve body first. That would require you to drop the pan, change the filter and fluid. You can inspect the pan for debris and check for valve body damage.

It is possible check balls are wearing the seat out into the separator plate and valve springs have broken causing weird shifting.

 

[rockola1971]

Could be in the valve body, stuck servo and/or burnt up 2-4 band. You will never get 2nd and 4th gear if the band is not holding the sunshell stationary for a shift to 2nd or 4th. Check your fluid on dipstick? Is it brownish/orangish? Is it nice bright pink? Does it smell like total a$$ and burnt? If its burnt then the 2-4 band likely burnt up which could be just its time to go because its worn out OR something like the servo stuck or valvebody hosed cause it to fail. Either way its a total rebuild if that band has been slipping and has failed. Youve got material all over inside the tranny, the clutches have been contaminated too and nothing is going to save it.
I limped a 99 Sierra with this problem 200 miles roundtrip to work a day for weeks until I was able to get it rebuilt. Just feather the throttle from 1st to 3rd and it will eventually make it into 3rd. Put gearshift into 3rd so it never tries to goto 4th (OD).

 

[exp500]

Make sure your OBD port works! Take a look at a wiring /fuse/ground diagram. I think problems are connected.

 

[rockola1971]

Make sure your OBD port works! Take a look at a wiring /fuse/ground diagram. I think problems are connected.

Unless a OBD2 signal line from PCM is grounded, the port has nothing to do with the transmission whatsoever. The port is merely an extension of existing wiring. But I imagine if the OBD2 signal from PCM was grounded that could definitely cause some havoc.

 

[exp500]

And it makes it tough to get trans codes. Ground and short issues after 20 years? Leaky computer plug? Lots of possibilities, but I'm not there to look. He likely has other electric issues along with this.