http://www.news24houston.com/content/headl...D=30633&SecID=2 For Your Car: Cooling systems 6/13/2004 6:24 AM By: Ken Collins Today, Rob Stettler, a technical trainer for Toyota in the southeast region, is going to explain to us how the Toyota Prius' cooling system operates. “The Toyota Prius has two individual cooling systems on it. The first cooling system is for the engine. The second cooling system is for the inverter/converter and transmission,†Stettler says. “First, let me explain to you why we have an inverter/converter on this vehicle. The reason is the transmission can only generate AC current. We can't store AC current on this vehicle so we have to invert it to DC current. WATCH THE VIDEO “DC current is stored in the high-voltage battery pack on this vehicle. When this process happens, we generate heat. This heat needs to be pulled away from this inverter/converter and be transferred out to the radiator on this vehicle. “The cooling system on the engine side works like a conventional car. The cooling system on the hybrid side of the vehicle has its own separate reservoir, has its own separate radiator. “It does use the same type of coolant as the engine side, however the coolant changing procedure is different and for this reason I recommend you take it to your Toyota dealer.†You will be seeing more and more makes and models with these hybrid systems and that's a great trend with gas prices going up.
Re: well that explains it actually, the technician mis-spoke: dc-to-ac is what an "inverter" does. "converter" might be used more commonly for ac-to-dc, though normally they're just called "power supplies" in most things we plug in . AND, the split cooling system answer does support my theory that on an extreme long downhill, MG1 and MG2 might be able to soak up the excess energy that the drive battery doesn't need, and dissipate it through their own cooling system!
My Prius is a 2005. It has 75,000 miles. It has only been serviced by the dealer. Why has the inverter pump gone out? The dealer mechanic says there are no pumps in the US, so I'll be out of a car for 2 weeks. He's given me a loaner but that's beside the point. I'm INTENSELY disappointed with this. I feel certain this is something I should not have to endure. Your explanation was good, but didn't tell details about service an maintenance process.
The pump has been identified by the owner community as a weak spot, to the point where some recommend replacement as a preventive maintenance measure. See this writeup for more: Inverter Pump At the end of that are two links back to PriusChat discussions on the subject, and there are others as well; do a good search. My guess is that the backorder status is from more failures occurring than Toyota anticipated. Let's hope they ramp up production as (inevitably) more failures occur in the GII Prius. I agree that you shouldn't have to wait so long. Be thankful, however, the dealer offered you a loaner. It's an out-of-warranty repair, and I'm sure many dealers wouldn't do the same.
On 9/2, my 2004 w/38k did same thing. Took to dealer that day and they gave me loaner and said pump might not be available for 3 weeks. So I call at 2 1/2 weeks and they say 10/21 which would be 7 weeks out of service. Called 2 other nearby dealers and they had 7 & 8 of the pumps in stock. Went and bought one and took to my dealer to install. Make a stink with the toyota complaint line and you may get some type of satisfaction.
This thread was six years old, and shows how much more is commonly known today. The dealer has the car for weeks, what are they doing for the 12v. during the time? Has the pump been upgraded and that's why there are no national stocks (according to your dealer?)
I got very little info from serv advisier and serv mgr didnt return calls. The unit I bought from other dealer is the upgraded one per my serv advisdor. The rental car co asked me to take rental invoice over to dealer when I got car and my serv advisor showed me the $900+ tab for the rental which Toyota is paying of course. If I would of waited until 10/21, the tab would of been about $1700. He also tells me he has other customers complaining as many Prii have car pool stickers which of course most rental cars dont have so this is causing folks longer commutes. Someone at Toyota just doesnt get it.
