Help: Dealer maintenance trouble

[Patrick Wong]

Originally Posted by sgort2

I wonder how many other 1st gen. Priuses have had this problem, the EXACT same thing happened to me on Monday, car lost power on the freeway, took it in to Toyota of Carlsbad they assessed a failed inveter coolant pump, possibly failed inverter, and failed transaxle. The repair is estimated to cost ~$10K and Toyota corporate isn't willing to do anything even though the car is only 2500 miles past warranty.

Very interesting. Could you obtain the DTC (diagnostic trouble codes) that were logged, and post them.

The root cause of your problem probably was the failed inverter coolant pump. Since we are seeing an increasing number of such failures with Classic as well as 2G, I am wondering whether it makes sense for owners with higher mileage vehicles to do a preventive maintenance replacement of said pump - rather than wait for a failure that may lead to damage of much more expensive components.

[EZW1]

Because a failed inverter pump is so critical to operation of the vehicle, and may cause so much damage if it goes and the driver doesn't catch the overheat warning of the inverter, I would hope Toyota installs a coolant flow monitor on the pump that will shut the inverter down if the pump fails. Such a device is cheap and will prevent excessive repair costs for the consumer.

Kinda like the high pressure switch in the air conditioning system shutting it down if the freon is lost.

[sgort2]

i got a 3120 - transaxle assy malfunction and 3125 - inverter malfunction

and yes, i've heard it's VERY wise to replace the inverter pump at ~75K as you will not get a warning light once it quits

[blueberry]

So what would a replacement inverter pump cost as a preventative move?

[paprius4030]

I'd like to know that too, but I haven't heard of any of the taxi people or other fleet, high mileage users having this trouble?

[galaxee]

don't know exact part price but probably around $200 at dealer markup, and expect up to 3 hours labor. in the 2g, i haven't seen fried inverters due to this pump going that i can think of- in fact, someone once continued to limp the car along with all the lights on and still didn't fry the inverter. this appears to be a bigger problem in the classic.

you can't just shut down a powertrain system in the car upon something going wrong. the car won't shut down the engine if you have a catastrophic oil loss, it's up to the driver to notice the warning and get off the road safely.

[hschuck]

Do the 1G and 2G cars use the same pump? Is there a pump p/n change between early and late gen2 2G models?

[edthefox5]

There sure is a market for a product that can monitor inverter coolant temp. Why didn't Toyota put a temp monitor in the inverter coolant stream?
What am I saying...they never even put a coolant temp monitor in the car!
You have to buy a Scan gauge for that. Wish I could see inverter coolant though with mine.
How about a little aftermarket underhood box that emits a loud underhood squeal if temps go over 190 degree's inverter coolant temp with a sensor that you apply to one of the coolant hoses on the inverter. I'd buy one if I owned a Gen1 car or if my 07 car was approaching 50K+. I have a good warranty on my 07 but I'd much rather take it to the dealer with a bad pump than a blown inverter. With the economy continuing to go south the dealer service dept will try to void your warranty at every turn as they look to the service dept as a profit center more & more.
$89 for the box could save you $4000. if you are out of warranty. PriusShop...knock one out!!!

This car really needs an engine temp monitor and an inverter temp monitor in its display system.
You lose the inverter out of warranty and its a done deal. Inverter coolant pump is obviously a sore spot with +100K cars.
On a side note..Posters..please post maintenance levels on your Gen1 trans.

[edthefox5]

Been thinking about this and I wonder if a low volt condition with high load is whats killing the field coils in the MG's. There have been a few Gen1 MG's with burnt windings. Nothing can burn up a motor winding faster then low volting it under load. The inverter goes over temp but continues to supply output power only lower volt until it finally fails. That condition would certainly overheat & destroy the MG windings.
The sore spot is the inverter coolant pump on this car.