Thanks Pr0230 for the tips,
I also wants to add my experience for experienced very loose e brake cable.
Before doing ebrake cable adjustment, I suggest examine whether the rear calipers are not seized.Based on numerous forum for XB/Matrix/Prius which all uses the integrated rear ebrakes , due to age and lack of maintenance ( not flushing brakes once every other yrs) and driving on rust belt the piston prone to sieize. To check that, use a rear brakes piston compression tool (press and turn , please don't use the dice , use one the one below) and try push the piston all the way back. If you experience huge difficulties to retract your caliper you might need to fix the caliper first before doing ebrake adjustment.
https://www.ebay.ca/itm/22PCS-Disc-Brak ... 0677.m4598