Gen 3 HV cooling fan motor: wiring diagram?

Can see it didn't change position. Here is my own 2010 build.

 

Does that power supply get the fan to move convincingly?

I notice on the label it is rated for two amps, while the BATT FAN fuse in the car is rated for ten.

 

I haven't tested it extensively for a long period yet, but i used 2A because Prolong charger use 1.9A and it works.

 

I figured out a sweet hack for bench testing (ok its not really on the bench) the cooling fan. I heat up a small glass of water & dip any one of the three temp sensors into it for about 5-10 seconds. If you have the dr prius app on you can watch the temp rise above 100 if the fan hasnt come on by 100 it aint going to. Every one I tested so far came on strong enough to feel the air blowing up outa the modules. The little fans are very quiet even at full blast. So if yours is noisy there is something wrong with it. I made a video showing how I do my hillbilly fan test on SaneAuto Youtube.

 

Does anyone know what the wiring diagram is for Prius C? I followed the information in this thread on my Prius and it works. However, when I tried the same way on my Prius C, it does not work.

I know here is for Prius. But I saw a thread in Prius C, and no body gives any answer, so I post the question here and hope some knowledgeable guys can provede some help.

 

Something interesting. When I supply a 12V DC to the fan connecter (+12V @IG0, ground @GND0 & SI0), I detected a 6.8V @VM0. Is this expected? I thought VM0 is isolated from all the other 3 pins.

 

VM0 is the blower speed feedback signal, used by the ECU to know what speed is being achieved.

By analogy to the gen 2 blower circuit, I think VM0 is expected to be lower (closer to GND) for higher selected blower speeds. (But it is a whole different circuit in gen 3 than gen 2, so I'm not sure if they preserved that same behavior. The one detail the gen 3 manual gives is that VM0-to-GND should be below 5 volts when the "blower is operating".)

 

Thank you very much @ChapmanF for the information. Do you mean Prius C has the same pinout as gen 2?

The fan in Prius C has the same type of connector as in Gen 3 Prius. Since I don't know the pinout and terminology of the Prius C connector, I use the layout in post #3 to denote Prius C. When I say "VM0", I refer to the upleft pin the post #3.

When I supply power to the Prius C connector following post #13，"VM0" shows 6.8V. The car's 12V battery is disconnected, so where does "VM0" get its voltage?

 

What I meant in post #27 is that there was a wholesale change to the blower and controller design between gen 2 and gen 3. Gen 2 used a simple 2-terminal motor and a separate controller. Gen 3 moved the controller circuit inside the motor, and also uses a different type of motor. Prius c came after the gen 3 liftback, so I assume it has the same kind of integrated-controller brushless motor as used in gen 3.

Nevertheless, gen 2 had a "VM0" feedback signal going back to the ECU, and so does gen 3 (and c).

In gen 2, because the motor and controller were separate, you could take a simple look at the wiring diagram and see for yourself that VM0 would be a voltage signal decreasing as requested fan speed increased.

In gen 3, because the controller is built into the motor, it's more of a black box. The diagram doesn't show the same level of detail. It might be fair to assume Toyota designed the new gen 3 integrated controller to provide the same sort of VM0 feedback that the gen 2 design did.

But that's an assumption. The manual doesn't describe the VM0 feedback signal in any more detail than to say it should be below 5 volts to ground whenever the blower is operating (at any speed). (That is, of course, consistent with it still being a voltage that goes lower as requested speed goes higher, and that's what I assume it still is. But just "below 5 V at any operating speed" clearly isn't enough detail if you want to pin down the behavior completely.)

VM0 is a feedback signal sent to the ECU, from the blower motor/controller, which you are powering with the connections shown in post #13.

 

Thank you @ChapmanF again for your reply. I didn't make myself clear. When supplying power and measuring voltage, I disconnected the blower motor. All wiring and measurement were done on the male side of the connector (disconnected from motor).

 

So you're measuring the ECU's VM0 input, when nothing is connected to it?

It may read some float voltage in those circumstances.

But maybe I still don't understand you. All the wiring and measurement you've been doing has been at the car's wire-harness connector, with the motor unplugged from it?

That isn't at all what post #13 is about, which you mentioned earlier. What is it you're trying to accomplish?

 

What I'm trying to do is to turn on the blower during grid charging while both the hybrid battery safety plug and the 12V auxiliary battery are disconnected.

To run the blower, I supply my own 12 VDC to be blower by tapping in the 3 wires as depictured in post #13 from the car's wire-harness connector. It works on my 2012 Prius.

When I tried the same way on my 2012 Prius C, the blower didn't run. So I unpluged the wire-harness connector from the blower, and measured the voltages of the 4 pins in the wire-harness connector. Via the tappings, the IG0 pin was still connected to the 12V+ of my 12 VDC supply, and GND0 and SI0 pins were connected to the ground output of my 12 VDC supply. Pin VM0 in the wire-harness connector was not directly connected to my 12 VDC power supply, that's why I didn't expected it had any voltage, unless it was connected to the IG0 wire somewhere inside the car's harness system.

 

So what you've done on your Prius liftback is power the blower while it's still connected to the car harness, by backprobing or tapping into the fully-connected wiring?

I think you may be breaking new ground doing that; it doesn't appear to be what anyone else earlier in the thread was talking about. They've been talking about testing the blower on the bench, with a power supply connected to it in place of the car wiring. The photo in #21 gives the idea.



Interesting that it seems to work ok in the liftback. Your power supply would be backfeeding the car's IG0 circuit (which seems in the liftback to not be much of anything if the BATT FAN relay is off), and the jumper from SI0 to ground is pulling down the ECU's SI0 output (which might be something the ECU wiggles by pulling to ground anyway, which could be the reason no magic smoke has escaped).

Something in the c might be different. You may end up looking in the wiring diagram to find out what.

Toyota Service Information and Where To Find It | PriusChat

 

When using a grid charger on the hybrid battery, the orange safety plug should be installed. The grid charger will not work if the safety plug is disconnected.

 

You are correct. I meant to say "To test my control of the blower with both the hybrid battery safety plug and the 12V auxiliary battery disconnected". Good catch!