stuck 2 wire connector to coolant storage/drain for drain/refill

USUALLY you have to squeeze a small tab on it to release but can you upload and post a close PIC of it?

 

Often those plugs are the harder part of working on modern cars. Last valve job I did I had to figure out how to unplug about ten connectors, all different, and it took about ten minutes, often a paperclip or tiny screwdriver, and a third hand for each. The actual wrench work took less time than that.

 

Why on you trying to remove the water temp sensor?

 

He pulled the plug for the CHRS pump motor, next to the coolant drain. The instructions I followed in my Bentley book had me do that, too.

 

I do not know why that would be necessary. What does Bentley say about the procedure to drain and fill the CHRS canister?

 

I don't know why, either, but it looked official so I followed the step. Much of Bentley's detailed instruction, what little there is, seems to exactly follow Toyota's procedures. I assumed it had something to do with keeping the OBD system happier during the procedure. Maybe it returns the three way valve to a certain position.

I'm not sure I understand the question, and right now the book is loaned out anyway. Is there a need to drain and fill only the canister, without draining and filling the whole system?

 

The Toyota service procedure includes a step to connect the CHRS pump connector. However it does not include a prior step to disconnect that connector. It also uses Techstream to run the CHRS pump motor.

As a practical matter, I see no reason to disconnect the pump connector as long as the car is IG-OFF when you are draining the engine coolant.

 

Well that's odd. Maybe the Bentley crew, in their wisdom, saw fit to add an apparently missing step. Perhaps it's a compounding of errors. Maybe the Toyota procedure has an extraneous step, an editing mistake, and nothing needs to be done with that connector after all.

 

Well...the main issue is for a first time FULL coolant drain its a real pia to get the air out. I did it and won't do it again. Its tough because of the CHRS.
In my very humble opinion your much much better off just dumping the rad once a month for a few months. That really helps.

Much safer than exposing your cars engine to an overheat from a poorly performed change. Seen so many posts that even the dealer messes it up. I wouldn't try it without at least a Scangauge to monitor engine temp.

If the op continues on a full dump don't forget the engine dump bolt. Its under the exhaust mani.

Btw, the engine coolant lasts a long long time. Your much better off putting that energy into changing the Inverterr fluid. Its quite easy and a breeze to get the air out and you get an instant bump in mpg's. The Inverter is the heart and soul of this car. Happy Inverter Happy life.
I do mine every 30K miles when I do my trans fluid and evap coil cleaning.