My Scanguage2 doesn't read these codes. It needs a more advanced tool. Even if the fault is removed, the computer may need a reset before the warnings go away. I'll try to poke around in there this weekend look for obvious things.

 

Here is a diagram for a 2009. The latest I got. According to the troubleshooting procedure you pictured above, all the wire color and terminal number line up OK.

 

Thanks. Does your source describe the location of G103?

 

For a 2009 it is item no 5 under the engine cover.

 

Ohhh and since the TCM is using the engine as a grounding point then you should have a good ground from the engine to the body as well.
If you suspect a bad ground maybe measure the resistance between the engine and the negative terminal of the battery, Should be a sharp zero,

 

The best way to check a connection is doing a voltage drop test, WHEN THE CIRCUIT IS UNDER LOAD. One strand of wire can give a low resistance reading and yet will not work if any amount of current is required to be passed thru the circuit.

 

@hanky
wire resistance does not change with current

 

The van would not run at all without those relays working.

I just finished probing all the wires at the TCM. It has power and good ground to the engine block and battery. Crank/IGN power is good. Wake up signal is good, and there's 2.5V on the data network lines too. That should be all it needs to work and respond, so I can only conclude that the TCM is fried.

 

One last thing you could try is to disconnect the battery maybe overnight and see what a good reboot might do. I dont believe much ... but worth a try.

Some have reported reflashing the ECM has cured the U0101. See with a dealer ?

 

ECM works fine. Engine runs. It's only the TCM that doesn't respond to the other modules, or diagnostic tools.

I unplugged the battery for about 1/2h. Engine light goes out, but comes back soon after a bit of driving.