Possible 2nd Hybrid System Failure

90K mile hybrid failure, I don't believe it. You have a problem somewhere, and your dealership misdiagnosed it the first time. Good news is that you got a new battery for free, so yippee.

It sounds like an inverter coolant problem if I had to guess with limited info. After driving a while, it got hot, and shut down. In this situation you won't be able to go anywhere. Easy to check. Have you had the inverter coolant pump replaced under the recall? Open up the top of the fluid reservoir and see if there is any turbulence with the car in READY.

Another possible issue that's fairly common and causes incorrect traction battery diagnosis would include the 12v battery being nearly dead. It can be way past dead when compared to a normal car, but still start the Prius. Then when driving the load will be quite high. Your mpg will suffer a bit, the 12v will get hot, and your inverter will work overtime.

 

We have seen a number of cases where the dealership did not diagnose the car properly. If possible please list the DTC's that were read. I agree with the above, that the 12V is suspect until proven otherwise. Also, perhaps there is still air in the coolant system. That too has happened before.

 

Keep in mind that the inverter coolant loop is a very critical part of the hybrid drive. Did the first "failure" occur before or after you had the recall work performed for the coolant pump? Dealer techs are people and make mistakes. Unfortunately making a mistake in this very complicated system means catastrophic failure. The good news is that the Prius lights up to tell you it is in pain, and then shuts off the effected systems so you don't run it into the ground. It is not uncommon for techs to not bleed the system properly and there is air in the loop. Or not to tighten one of the parts all the way and over time the coolant leaks out, etc, etc, etc.

If you can check the turbulence in the reservoir really quickly, now would be a good time. Takes 30 seconds.

 

Could be multiple failures of different items all close together

 

See what the Mechanic says.

 

I've had two inverter pumps fail one after the other and through no fault of the Hybrid system. As mentioned above double check the turbulence again and failing that not more can me done until the codes are retrieved as there are too many variables to deal with.

Good luck,

Gavin.
Current Tech Auto Electrical.

 

I'm having a similar problem. The first time it occurred, the red triangle came up and the tire pressure warning light. I turned off the car and tried to restart, several more warning lights and now the car won't start. The dealre replaced the auxillary battery and sent me on my way.

I was driving on the free way, same thing. The red triangle and the tire pressure warning light come on I drive to my destination and turn the car off and try to restart, car won't start.

I get towed to the dealer and they diagnose the inverter. I get the inverter replaced, drive home, stop for dinner, pull out of the restaurant, drive a 1/4 mile, the red triangle comes on again with the tire pressure warning light. I get home, try to start the car, all the same warning lights come on and the car will not start again.

Ideas?

 

That sounds like a very different problem. I suspect the 12V battery is not being charged, which is what the dealer suspected when they replaced the inverter. Since it is still the same, they just guessed the problem without really looking into the situation. It is necessary to get codes read and listed here, although if the battery is going completely flat, they may be getting erased. A voltmeter reading of the 12V battery is a place to start. Put a charger on it and make sure it is completely full, and then test to make sure it is being charged by the inverter when the car is in Ready mode.

Please list the numbers from this test:

Entering Maintenance Mode (aka 12V Battery Check) without Switching Headlights ON/OFF | PriusChat

 

DTC P0AA6, info code 526 means that your car has a high voltage leak, but it does not necessarily mean the inverter is the problem. Any component in contact with high voltage could be the problem: traction battery, traction battery ECU, high voltage cabling, inverter, or transaxle.

Typically, another three-digit info code (ranging from 611 to 614) will appear which will help to narrow down the issue. I assume that your car is under hybrid system warranty?

This problem has nothing to do with your tire pressure warning light or that system.

How about posting sharp photos of the warning lights and icons that appear?

 

The A/C compressor is also in that list of HV leakage possibilities. Has the A/C ever been serviced?

 

Here are pictures of the warning indicators.

 

The first photo shows the hybrid vehicle warning icon. That tells you there is something wrong with the hybrid system.

The second photo shows the master warning red triangle, which just tells you that something is wrong. I believe the first amber light is the traction slip warning light. The second amber light is the brake system warning light. The ABS and check engine lights also are on. So this shows you that the skid control and engine ECUs have logged DTC as well.

Therefore, there should be DTC besides P0AA6.

 

When the inverter coolant pump fails and the inverter begins overheating, one of the first system to shut down is the DC to DC converter which provides the charging to the auxiliary battery. One consequence of this is that sometimes the DTC's get lost and the problem misdiagnosed. This might be the case here.

See above.