Code U0101?

The voltage on pin 86 may not be an issue if the transmission is engaging because I suspect you are not checking it the way we need to in order to prove it is working.

Pin 86 should be the ground to the TCM so that the TCM can control the relay on and off.

It does this by grounding this circuit which completes the circuit and closes the relay.

So, to check this we need to move your red lead of the meter to battery positive and then put the negative lead on pin 86. Then turn the engine on and the TCM should ground the circuit and that will show that this is operating.

https://www.2carpros.com/articles/how-to-check-wiring

However, the issue with the code is most likely a wiring issue or the TCM is not operating.

The U0101 code is telling us that the TCM has a communication error.

This is normally a wiring issue or the TCM itself has failed.

I am attaching the info below on this code but here is a guide that talks about this communication network.

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

As you will see we have an issue either with the wiring harness B or the TCM.

The way to read this is to look at the last chart as this code should be in the PCM. It is saying that the TCM is the only one with a fault and the location would be harness B or the TCM.

Since this is the only code, I am going to think the TCM is the issue.

Let's run through this and go from there.

Thanks

Okay, let's check for power at fuse # EngB+ and TCM fuse in the under-hood fuse panel. Here is a guide and I have included the transmission wiring diagrams so you can see how the system works:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Check out the diagrams (below). Please let us know what happens.

P01C1 code is Transmission - BBV Sensor Circuit Low Voltage - TFP Valve Position Switch-Drive Without Drive Ratio which has to do with the camshaft timing actuator. I would make sure the engine is full of clean oil with a new filter and then remove the actuator to make sure it is not clogged with flecks of metal or sludge. Here is the location and a generic guide on how to change the oil and the VCT valve in the images below #1.

https://www.2carpros.com/articles/how-to-change-engine-oil-and-filter

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

Yep, that is a system error, it could be the clusters is causing these issues, but I would check the ground to engine and body from the battery, also we need to do a CAN Scan, you can get a CAN scanner (Controller Area Network) from Amazon for about $30.00.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

Here is a scanner link:

https://amzn.to/3o41KcZ