All, thank you for your assistance.

2006 T4R sr5 2wd v6

This began with the 4R not turning off when the ignition switch was turned to the OFF position and the key could be removed and the engine would continue to run. It could also manifest as a failure to crank - turn key - nothing happens.

The ignition switch has no spring tension. The key does not return to any position under spring tension.
At times it will spin 360 degrees with no resistance and at other times, it is normal but with no spring tension.
Purchased new ignition cylinder. It has no spring tension either.
4R will not start with the new ignition cylinder. The battery is new. It is not the relays. It is not the starter. It is not the fuses.

What provides spring tension to the ignition switch?

Any ideas?

Ignition Lock Cylinder Barrel Rod # 2054a The rod had snapped. There is no direct replacement part that I have found.
Salvage yard steering column - preferably with KEYS. $75-100. Half an hour. 10 mm socket, s-m phillips short in length, a sturdy piece of 8-10" in length of 10-12 GA wire with a 1/4" bend in the end or equivalent tool, needle nose pliers.
Toyota replacement part $450 3-4 hours labor @ whatever it is in your area.

Remove the panel that has the hood release attached to it. Remove the Immobilizer - unplug and pull forward. Insert the ignition key and then turn the key 1 place to the right or CW - use the tool to depress a detent in the hole at 12 o'clock about an inch and a half back on top of the tube assembly to the right of the steering column.
Wiggle the key and pull while pushing down with the wire in the hole. The lock comes out. The ILCBR #2054A is what remains in the hole. Take the electrical connector off of the back end of the tube - Phillips head screws (2).
Rotate the other end of the ILCBR until the notch aligns with the slot and push it into the tube. Use wire to fish it out. Using the same technique remove the lock cylinder and then Take a PICTURE of and then remove the ILCBR from the salvage steering column.
Place it in the vehicle's tube in the same orientation using the reverse of the same technique above for the removal of the broken piece. Replace the ignition lock cylinder - the ignition key is in the same position as coming out above. Replace the immobilizer and plug it in. Replace the switch on the end and plug it in.

It is not necessary to replace the entire ignition lock tube assembly and breakaway bolts.

Girl Power!

I am not sure what this is below. However, it is not pertinent to the ILCBR or this thread.