Rebuilt Trans help

So i am still having shift engage issues. I checked the level of fluid it is fine, the color is still fine. When i let off the gas it doesnt cruise well just slows down. When there is a shift sometimes it goes up about 250-500 rpm and stays there till it finally shifts. Any ideas? Thanks once again.

Well, kinda sounds like poor line pressure. Would be interesting to see what the scan data says about commanded pressure versus actual pressure while watching the input and output rpm values. What you are describing is also known as “shift flare”. Tell us, once engaged is there any hint of slipping, such as an unusual rpm rise when you squeeze the throttle but not enough to downshift? If you don’t have the equipment, a competent transmission shop should be able to do a line pressure test for a reasonable fee which will tell a great deal about what is going on.

Sounds like it’s hanging. How many miles are on the tran’s? Last time it had a flush and filter change? I know my old tran’s would do really hard shifts at times. I found out the filter was starting to get clogged and wouldn’t allow good flow within the system causing pressure issues. Just because the fluid looks good doesn’t mean the filter isn’t clogged or etc. Maybe start with something like that first.

I can do a line pressure test at school. The trans was rebuilt less than 4000 miles ago.

Today I hooked up IDS scan tool. I compared shift solenoids to the solenoid app chart. They arent working properly. I hooked up the NGS and I put on the output test. I could turn the fan on low and high but they all wouldnt come on at the same time. The solenoids wouldnt turn on or off. Trans is at 5 grand going 60 mph.

Get the pinout chart for the PCM connector and check the trans solenoid circuits. Don’t forget to check for power and ground at the trans connector and that your trans range sensor is working/adjusted properly.

you got a shafer shifter at school? hook that up and see if you can shift it manually. Also on a side note you could wire a series of HD switches to actually shift the car temporarily. As shifts are nothing more than a series of ons and offs and certain rpms.

I could look up the pin out and possibly do a right up for this.

There is good continuity, there isnt enough current flowing, and there is a voltage drop when i try switching on the solenoids to shift.alldata says to now diagnose by system.

Run a voltage drop check of the grounds, especially driveline to body and battery to body. This sounds like a bogus ground connection.

we did a voltage drop test with a dvom. Used the battery terminal negative for ground and had the positive lead to the solenoid pins. there was a voltage drop to each one.

The system grounds, man, the system grounds. The PCM grounds the solenoids, but that ground path goes out on the PCM grounds. Find 'em and check 'em. I don’t recall immediately the exact locations, I use pictures so I don’t have to remember such minutiae. Checking my workshop manual . . . . . no good, it’s not the electrical manual, just the how to do stuff and troubleshoot. If I can remember, I’ll look up on Alldata tomorrow at work.
If the PCM grounds aren’t good, the actuators can’t work properly. If you have the connector information, you can use output state test mode to cycle the solenoid signals and probe each circuit at the trans connector to see if it drops to near zero volts when cycled on.