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Discussion Starter #1
Well it is getting a bit cooler here in Canada and my drivers side blend servo took a dump and stuck on cold. Found one on the bay cheap (used) Same part # etc.
Went to install it and it does not work. I have no wiring diagrams on this.
Is it just plug it in and it works or is there a process or initialization that I have to do? I think me used one is no good but thought I would ask. It does have a 100% guaranty.
FYI $80.00 Canadian to my door. Shipping is bad to Canada.
 

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Syncing it to the system is most likely required. Reboot and it should be recognized.

The servos on the Gen-II vans were 5 wire: 2 for the motor drive, and 3 for a voltage divider (potentiometer) who's feedback was used to track the position. Dedicated wiring to each component was used for component tracking.

The Gen-III system is only 3 wire, and has a chip inside each unit to tell the CAN bus system which servo it is, and it's position. It's a ring, without dedicated wiring. When you take one out and replace it, the system needs to query all servos in the network and confirm the roll of each (location) and current position. It's unlikely to do the 'assign' part on each normal start-up. That's a reboot duty.
 

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Discussion Starter #5
OK. Thanks. I will reboot the system tomorrow. My son has his driving test in the AM. I will do it after that.

FYI: My used one came with a different gear on it as this servo is used on different vehicles. No biggie to change over the gear. The part# on the main unit is the same.
 

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FYI: My used one came with a different gear on it as this servo is used on different vehicles. No biggie to change over the gear. The part# on the main unit is the same.
Interesting.... So while the body has the same part number, the whole assembly must have a different part number for the application (body & gear). I wonder exactly how specific the ID code of the chip inside is, and if it will sync? Probably yes as the body code matches, but things are getting to be more difficult as point-to-point wiring goes away in favor of networking.
 

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Discussion Starter #7
Honestly have no idea. Both units have 5 pins on the servo but as you said only 3 are used. Only 3 wires at the plug.

Well. Disconnected the battery and no dice. It did move very slightly after a bit of turning the temp dial back and forth. If I have a chance I will run down to my buddies shop and hook it up to a techstream. Look at the numbers etc.
 

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Discussion Starter #8
UPDATE:
Took my Sienna to my friend. It had a code B1446. (Air Mix damper control servo motor- Drivers side) Cleared the code and it worked. Lined up the gears and all is good...

All I can think is maybe I did not leave the battery disconnected long enough when I switched the servo over?? It is the only thing that makes sense. I had it off for 5 mins. Maybe a capacitor in the AC amplifier??
 

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20 minutes left alone, or some serious load to ensure it's really dead. Did you turn on the lights, step on the brake pedal, etc., to thoroughly discharge the system?
 

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UPDATE:
Took my Sienna to my friend. It had a code B1446. (Air Mix damper control servo motor- Drivers side) Cleared the code and it worked. Lined up the gears and all is good...

All I can think is maybe I did not leave the battery disconnected long enough when I switched the servo over?? It is the only thing that makes sense. I had it off for 5 mins. Maybe a capacitor in the AC amplifier??
I thought about this thread yesterday when I saw a thread on a Lexus LS460 forum about a similar problem. The problem on the LS460 was resolved through Techstream: "Body Electrical / Air Conditioner / Utility / AC Servomotor Initialization".

I know that Sienna and LS460 appear to be very different animals but there is much in common between the least expensive and most expensive vehicles Toyota makes. Is there be a similar Techstream AC servomotor initialization for the Sienna?
 

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Discussion Starter #12
I thought about this thread yesterday when I saw a thread on a Lexus LS460 forum about a similar problem. The problem on the LS460 was resolved through Techstream: "Body Electrical / Air Conditioner / Utility / AC Servomotor Initialization".

I know that Sienna and LS460 appear to be very different animals but there is much in common between the least expensive and most expensive vehicles Toyota makes. Is there be a similar Techstream AC servomotor initialization for the Sienna?
As mine is a base model with manual AC I did not see that screen. Maybe for automatic AC?
 

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Discussion Starter #14
Sorry. I was a bit misleading on my UPDATE. My old servo was toast. This was the new/used servo that I put in. After clearing the code it worked like it should.
 

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Good info. Power cycling alone might not fix the issue. You needed Techstream to clear the fail code in order to get it to initialize.

I'm attempting to help someone on another Toyota board who might be in the same boat, so this helps.
 
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