Found after experimenting with a 2009 T&C the transmission power relay is in fact controlled by PWM of about 65%. Cannot imagine why or what advantage to this, and why only this one relay out of all the others that are on/off.

Anyway the real problem is the rising T15 voltage from the PCM when key off. 2.6V on T15 is enough for TIPM to turn on trans relay, apparently TIPM senses the voltage, with no measurable current flow. Where the circuit lights a test bulb when on, tried hooking up a relay with T15 on one side of coil and one side of switch with other coil side grounded, other side of switch to TIPM, it wouldn't buy it and set P0882 Relay Low code. Then tried not interrupting T15 but tapped it to relay coil with other grounded. This did work with the coil resistance pulling T15 to 0V when off, and then energizing the coil when key on, with TIPM responding and all else working properly.

Thinking now a much higher resistance to ground will pull the leakage down, and not flow enough current to be an issue when circuit is high. Tomorrow will start with 5000 ohms, measure voltage when off and current through resistor when on. It really should have a new PCM, but if this only trouble can be corrected with just a resistor, then why not? Also wrongly spent $$$ on new TIPM that cannot be returned, will try to find a home on eBay to recover something. I believe can be configured to another vehicle with "Restore Vehicle Configuration" function online with wiTECH.

Kevin from Maine