How to bleed engine coolant loop with Techstream?

While Techstream has purpose-built "bleed procedures" for the brakes, I don't think it's got anything quite like that for burping the coolant.

I think the most you're looking for there is how to enter maintenance mode (so the engine won't shut off while you're trying to burp it), and the "enhanced OBD-II active test" to run the coolant heat storage tank water pump.

Maintenance mode you can also enter by doing the right kind of dance with the go pedal and shift knob, but for the thermos pump, you pretty much do need the scan tool.

If you have the repair manual in PDF but no table of contents is showing up, you could try a text search for "ADD ENGINE COOLANT".

Will the long end of your L-shaped wrench reach?

 

In the 2007 Prius Repair Manual (RM03Q0U) (more info), see the topic Engine/Hybrid System: 1NZ-FXE Cooling: Coolant: On-Vehicle Inspection. In older editions, it’s towards the beginning of the CO (1NZ-FXE Cooling) pages.

As @ChapmanF kindly notes, the Toyota Techstream diagnostic system doesn’t have an air bleeding function, as such, for the engine coolant. Instead, the procedure just tells you to run the water pump and then the engine.

The 2007 Repair Manual was written for users of Toyota’s earlier Intelligent Tester (Diagnostic Tester) device, but the 2008 edition gives the Techstream path “Powertrain / Engine and ECT / Data List / Activate the Water Pump.” I think this has a misprint, however: “Data List” should be “Active Test,” since you’re controlling the vehicle, not just observing its status, and indeed, the path is given with “Active Test” in the procedure for diagnostic trouble code P2601, elsewhere in the manual.

 

Do not even think about doing that. It’s an airlock nightmare.

All you need to do is dump the rad. It’s got a dump petcock on the drivers side behind the hoses on the bottom of the rad, Dump it throw in a gallon of LLC. Drive away.NO AIRLOCK NO BLEED NO TECHSTREAM.

Do it again in a few weeks. Then if you don’t like that do it again. It works.
Engine coolant is not a big deal on this car.

The G2 Prius is very easy on the engine coolant. But very hard on the inverter coolant so concentrate more on that and it’s good bang for your buck as your mileage will increase with pristine inverter coolant and will greatly extend the life of the inverter pump.

The G2 Inverter is the heart and soul of this car. Keep it happy.
I changed my inverter coolant 3 times over 15 years with this car it’s easy.
Always threw in a bottle of Redline Water wetter too with every change.
Inverter loved it ran very cool as I checked it with an IR thermometer.