Although the van was essentially problem free during the 12,500 miles of our summer trip, we developed a problem a couple of days after our arrival home. The van is a 1999 Toyota Sienna and after 225,000 miles the power door failed. I was a little disappointed as I knew the replacement cost was high. Although it was only the cable that opened the door that failed, the fix is a total replacement of the power door motor. Sure enough a used one on ebay was $400. A new power door opener from Toyota runs from 1200-1700 dollars. Whew!
I removed the unit from the van after unhooking the cables from the door. This allowed the kids to use the door manually while I worked on the power opener. To do this I had to remove the plastic rail cover on the outside of the van and unbolt the corresponding rear hinge on the slider. The decorative slide cover only came off after breaking the two hidden clips near the taillight and removing a single 10mm screw in the door jam. After that the cover could slide forward and off the remaining clips. I reassembled the whole thing aside from the power unit so as to use the van's door manually for the next couple of days. It worked perfectly well as a manual door.
Using the piece of wire that broke off I went to Lowes to match it to the wire they offered. No dice. Off to Home Depot. Home Depot's wire had a thinner plastic sheath making the total thickness of the wire a little less than that offered by Lowes. I decided the match was close enough at 3/32". I also got a ferrule stop set. The total for the wires and the ferrules was less than $5. The crimping tool was borrowed but can be purchased for around $50.
Once home I took the back plate off the power door unit. There was no debris inside the unit due to the old wire's sheathing having failed. I had read in some postings before attempting this fix that the dealers claimed that the old sheathing would damage the inside of the power door unit. I don't see how this is possible. Although it is made out of plastic the plastic is high quality. It is likely a lie in an effort to sell more product.
With the replacement wire in hand I laid the new wire next to the old and marked the length of the old wire on the new. I cut it on the mark. Duplicating the length of the new wire is important. I removed the sheathing from the end of the new wire and swaged an end on the new wire. I found that I could feed the new wire through the unit from the inside to the outside easier than feeding it the other way. I laid the repaired end of the wire in the door adjustment piece. This is the piece that removes slack in the wire if it is too long or adds wire if the line is too tight. This adjustment is done once the motor is mounted and the door is back on with both cables attached. The has to be closed and it is best to pull the wire that closes the door down and so that it hangs loosely. This removes all the closeing wire from the power closer.
I remounted the power door unit in the van to work on the on the other end of the new wire that attaches to the door. This end was somewhat proprietary and I felt it would be difficult to replace. The old wire within a couple of inches of the proprietary end was still in good shape so I decided to reuse the old end that attached to the door. This meant attaching a little bit of old wire to the new wire. I snapped the old end back on the door and after removing the remaining slack with the adjuster mentioned earlier the door worked fine.
I mentioned the choice I describe below only briefly in the post above, but it is a valid path to take. The door will work perfectly well as an unpowered slider. (It will work just like the other slider on the driver's side including a functioning power door lock). In my case I needed the power door for my small children.
In the event that the repair becomes cost prohibitive you can disconnect the cables from the door. They clip in. Access is difficult and removing the rear knuckle that rides in the channel is required. Once it is unbolted from the door the rear of the door will want to fall.(Don't forget to scribe the position of the knuckle before unbolting for adjustment reasons during reassembly) While holding the door up I closed it so I could work on the knuckle. With the knuckle off the door it can be wiggled off the track and the cables unsnapped from it. At this point the door motor can be removed with the cables intact. In reassembling the door I had to let it rest on a box while I positioned the knuckle in its proper location as indicated by my scribing during disassembly.
Alternatively you can simply cut the two cables from the door near the knuckle and push the remaining amount into the van then use the door like the one on the driver's side. It will work very well as an unpowered slider.
2004-2009 power sliding door drive unit
Below is a picture of a power sliding door motor for a 2005 - 2009 Sienna. It is clearly more diminutive than the unit it replaced with a smaller gauge wire. This fits with the short lifespan these units seem to have. Many don't even manage 50k while my older style lasted approximately 220k.
It also appears in the photo that the pulley casing that the cable wraps around a pulley within is screwed together. Being that it can be disassembled it is likely that the wires within can be replaced.
Beyond that I can only apologize for the poor image.
Update: Two more pics, this time of a 2004 Sienna. The mechanism is mounted in the door in this photo. The red circle indicates the power door motor. These pics were lifted from the net as I have not actually worked on a 2004 body style door.
According to the comments below...
In the second picture of the 2004, the circled item is the _window motor_, not the door motor. The door motor is in the very lower right of the first picture.Anonymous appears to be correct when comparing the pic above of the door motor to the two pics below.