Transmission will not engage why?

When you hook the scan tool up, are there codes? If no codes, can you monitor the TCM and put it in gear. Does it show Drive or 1st gear as current gear?

If the manual gears are working but Drive is not then I suspect the TCM is the issue as the shift solenoids clearly are operating and the pressure is ok or it would still not move.

So we need to rule out a sensor issue or a TCM and we need a scan tool to do that. As you can see from the wiring diagram, the shift lever tells the TCM that it is in manual and then the TCM sends this signal to the shift solenoids. So as long as the TCM is seeing the shift to drive then it is not sending the signal to engage the solenoids.

Thanks

Good morning,

I would check the fluid level first to be sure the fluid is correct for allowing operation.

https://www.2carpros.com/articles/automatic-transmission-problems

The filter could be clogged in the transmission as well.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Beyond that, it could be an internal failure from the front pump or the torque converter.

Roy

That sounds like a mechanical failure. The wait for it to warm up earlier suggests worn seals that had to warm up and expand to work but it could be just low on fluid this guide will help you check it.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Please run down this guide and report back.

Since the transmission was recently rebuilt, my guess is the shifter was not secured correctly and somewhere a linkage has been dislodged. Check the shifter linkages for a start.

Yes, linkages are external part and it goes from transmission to shift lever.
You would need to get under vehicle to check.

Good morning,

If the filter and the fluid is clean, then it sounds like an internal failure in the transmission.

https://www.2carpros.com/articles/automatic-transmission-problems

Is the check engine light on? if it is, do you know the codes?

Does the cable work from the shifter to the transmission? if the car goes into park and does not move and comes out of park when you release the shifter, the cable is working.

Roy

Okay, I attached the procedure for the pressure regulating solenoid. This could be your issue. The procedure with pictures are below.

Roy

Snow mode or any of the others doesn't change the transmission engagement operation. It just changes shift points and other things but we need to check for codes. I am not sure how this would have happened or is related to the snow mode engagement. I think that is more of a coincidence.

Clearly if it didn't go back into gear, you had to have it towed. Did you tow it to a shop or back home? Do you have the ability to check codes? If there are no codes then we need to check fluid level and see where it is and the condition of the fluid.

I included the process on how to change the fluid and filter if it is low or in poor condition.

If you lost transmission fluid, you will not have any operation since it is hydraulic. It is more than likely the case that the fitting has came out of the radiator, and the radiator needs replaced. If the vehicle didn't run long after the mostion stopped, there should have been enough residual fluid in the pump to keep it lubricated. After it is able to hold is trans fluid, you should be fine.