I have attached the wiring diagram for the system to this message.
Can you please check all fuses in the under hood fuse box (TIPM)?
If you have no power at either side of fuse 24 with the ignition on and rear wiper switched on you may have a problem with the TIPM.
Do you have access to a scan tool?
Do all other functions work on the steering wheel multi-function switch work ie front wipers and lights?
If you can check with scan tool as to the status of the rear wiper switch input and rule out a multi-function switch issue, the relay for the rear wiper motor power is integral to the TIPM.
Hope this helps, let us know if you have further questions.
Images (Click to enlarge)
Sunday, February 9th, 2020 AT 10:44 PM