I have a dead Toyota Prius

Question

2007 Toyota Prius blown engine need to put in neutral to move but can’t turn on. Does anyone know how to put in neutral?

Answer 1

Is the battery fine? Charge the 12V battery, which should be in the trunk, but there should be jumper / charging connections under the hood.

Toyota uses a shift-by-wire functionality, so putting to neutral requires 12V battery to supply current to the electrical systems.

Note also that the transmission (a planetary gearbox with 3 shafts) and both of the 2 electric motors (which are located in the transmission) are continuously connected to the wheels. In fact, even the internal combustion engine (ICE) is continuously connected to the wheels and can't be disconnected, but the electric motors should spin free if in neutral, meaning the ICE shouldn't rotate if you push the car.

Are you sure it's just engine damage? Not transmission damage? Or parking mechanism damage? Because if the transmission or parking mechanism is damaged, you may be unable to push the car in neutral.

Edit: some basics on how a Prius transmission works:

There is a planetary gearbox with 3 shafts:

• Shaft #1 is connected to the wheels and motor-generator 2
• Shaft #2 is connected to the internal combustion engine (ICE)
• Shaft #3 is connected to motor-generator 1

If you push the car with ICE turned off, shaft #1 rotates in the direction of pushing the car. Shaft #2 is held still by the ICE. Shaft #3 rotates backwards, caused by shaft #2 being held still by ICE.

There is a relationship between the rotational speeds of shaft #1, shaft #2 and shaft #3, but basically there's two degrees of freedom, the relationship removing the third degree of freedom. So, if you have an additional constraint that shaft #2 is being held still, this removes an additional degree of freedom, so the remaining count of degrees of freedom is 1. This degree of freedom is basically the movement of the car forwards / backwards, and at the same time, MG1 rotates in the opposite direction.

There is no clutch in a Prius. The engine is continuously connected to the wheels, but the three shafts give an additional degree of freedom which allows electric CVT (e-CVT) transmission to work. The additional degree of freedom also allows the "neutral" gear to work.

Here's a Flash widget that explains how the power split device (the planetary gearbox) works: http://eahart.com/prius/psd/ ...but unfortunately, it requires Adobe Flash which is not the most secure plug-in out there.