Same thing happened to me - 04 Sienna xle

Just under 50k miles and the cable broke (rusted/frayed) and is hanging from under the rear window, passenger side. toyota svc said they can't just replace the cable, they have to replace the whole assembly, cost = $1500 (part is $1000). the broken cable was prohibiting the sliding door from opening all the way and thus kept closing on my kids. had to finally cut the cable from the inside to allow the door to open all the way and "lock" in the open position. what a pain!