Perhaps the most common cause of a Toyota Sienna’s doors not opening is a circuit overload, which occurs when the minivan’s doors are unable to latch due to a blockage. When this happens, the vehicle’s electric motor circuit may become overwhelmed, causing a fuse to be tripped. As a result, the doors will not close properly.
To check if this is the cause, manually open the doors and see if anything is obstructing the door’s upper and lower tracks. If there is, remove it.
The good news is that replacing a latch motor is relatively simple and inexpensive. Replacing a frayed cable may be a bit more complicated, but a seasoned mechanic should have no trouble with it. I hope your mom’s Toyota Sienna is running in tip-top shape in no time!