Red triangle and hybrid warning light, and Check engine light illuminated! Please help!

This afternoon, after driving about 150 miles, I came home and shut off my 2001 Prius. It was sitting for about 20 minutes before I turned it back on to drive off. Almost immediately, the hybrid warning light came on on the MFD, the red exclamation mark light illuminated, as well as the check engine light, and the motor shut off. I popped the hood, and could hear a high pitched squeal coming from near the inverter. I called my dealer to ask the service department what I should do, and they just told me to bring it in and they will take a look at it. I live over an hour away, so I don't want to bring it there if I can avoid it. I then shut it off and let it sit for a few hours. After reading about the possibility of the auxiliary battery being bad, I went and turned the Prius on, and then shut it off several times to reset the hybrid warning light (I had to do so in order to access the aux battery information through the MFD). It turned on without incident, and shut off fine, and after being reset the hybrid warning light shut off, as well as the red triangle light. Then, I went through the process of pulling up the battery voltage information through the MFD. With the car off, and the lights and fans off, the battery voltage read about 10.0-10.5 V. With the lights and fan on, the voltage dropped to about 9.5 V. After getting those readings, I drove it down the road a little ways, just going about 20 mph. It seemed to work fine. The check engine light is still illuminated. With the motor running, the voltage reading was 13.2 V, and then when I got back from my test drive and shut it off, the voltage hovered at 10.6 V with the lights and fan on.

Any ideas, anyone, if the auxiliary battery is bad, and caused this?

I have only had the warning lights come on one other time, right after installing cruise control, and I am quite certain that was related to removing the orange plug from the hybrid battery. After turning the car on and off enough times to reset it, it worked good following that incident.

I bought the car used a few months ago, and don't know if any fluids have ever been changed besides regular oil changes. It was a State of Minnesota vehicle for the first 90,000 miles of its life, and now has 154,000 on it. I bought it with 150,000. I'm pretty sure that the State of MN maintains their vehicles pretty well, I'm not sure if the previous owner did all the scheduled maintenance, however.

What options do I have for a scan tool under $100? I have read that the Ecrostech Mini-Scanner is one of the best options for the First Gen Prius, however they are unavailable now. Are there any other scanners that can pull diagnostic codes from ECU's besides the engine? Would a scanner that only reads DTC's from the engine be fine for most purposes?

Thanks so much in advance!

 

The inverter coolant was a little below the "low" level, and when I started it up, I did not see anything moving in there (perhaps it was a bad idea to start it with the low level). When I looked through the service history, I did not see anything for transaxle ATF or inverter coolant, although I do not have records from the time period that MN State owned the Prius. Is the inverter and regular coolant change that someone who is somewhat mechanically inclined can do, or does the dealer need to do that? And how about the transaxle ATF, is that something I can do?

From looking through the service records, and not finding anything from the previous owner, the battery could be at a minimum 6-7 years old. When I replace the battery, should I put in the OEM one, or an aftermarket upgrade?

Wow! If I get a VOM, I will be inclined to get one through Harbor Freight. So before replacing the aux battery, do you suggest I bring it somewhere and have it tested?

Ok, I will look through the discussions further.

Alright. I have heard the very high pitched noise before when I've had the car on and in ready mode before. I am pretty sure that the noise that I was hearing was different; it seemed like it was a little lower in pitch, with some fluctuations in intensity and pitch, as well. Are you referring to a potentially shorted cell in the aux battery, or hybrid battery? Just a bit ago, I went and checked the inverter coolant level, and it was slightly below low. I'm wondering if the variations in intensity and pitch of the squeal that I was hearing from the inverter was due to a low coolant level, without enough fluid available.


I should also mention that after my Prius was sitting for about 5 hours, I went and started it back up, and the check engine light was off. And also, the high pitched squeal that I was hearing- I heard the same noise when the warning lights came on following my cruise control installation, but during that incident the noise went away after the reset. Now, when I started it again, it seemed that the squeal coming from the inverter had not returned to the really high pitched noise that I have heard from that area before, but still varied in its intensity and pitch.

Thanks, all, for your assistance! I do hope that I will be able to get the issue sorted out. Another thing I should mention: When I start up my Prius when cold, the engine sounds somewhat rough for the first couple minutes of travel, and then seems to smooth out..I'm not sure if this is normal or not. The roughness at cold start just began when it got cold here in MN, and occurs when the temp is <40* F.

 

Thanks, Bob, I will be sure to keep this in mind when putting in a new battery.

 

Ok, that makes sense. I've read that one option is to put an aftermarket battery in. Do you recommend factory Toyota, or any particular aftermarket? And are you thinking that the inverter issue could be related to the 12V battery?

 

Ok, so it turns out that the battery in my Prius is an aftermarket Yuasa version. On the top, I see:

-S34B20L
-GS YUASA
-20HR 35Ah CCA 272A
-B20(JIS)
-16111W
-LB318 (SI)

I brought the battery in to my local Napa store, for a load test. The man working thought it was good, as his device told him it had 100% life and charge, and 190 cca. When he first hooked up his load tester, it read 12.8V, and then after he tested it, he got a reading of 12.5V.

The battery posts look much smaller than standard batteries, so I am thinking it has Japanese size posts..

Usnavystgc, if my inverter coolent level is too low, would the pump simply be unable to pull in any fluid, causing a lack of turbulence?

Thanks, all, for continuing to stick with me in getting this figured out!

 

I called my local Toyota dealer, and the parts department gentleman said that based on the information (part number) on my battery, that it is the original 12V battery. Of course, it could have been replaced at some point with an OEM battery, but certainly not recently, as the parts guy I talked to told me that the battery for the First Gen Prius has been changed multiple times..

Tomorrow, I plan to bring the battery to the dealer, and have them test it. When I tried hooking it up to my 1.5A trickle charger, the "problem" light on the charger lit up, and would not charge the battery.

 

After I get the battery sorted out, I will get back with the information on the inverter coolant!

 

Being I happened to be in the city where the Toyota Dealer is, I ended up bringing the battery to them, and the service tech said that it was good! They measured 290 CCA, 12.50 volts at 66 degrees F. SOC: about 60%, and SOH was closer on the chart to high than low. Why is their tool saying the battery is fine, when my MFD reported low readings for voltage?

Dealer said being I took battery out, they would be unable to pull codes, and to bring it in again if I have the same problem.

So, I bought some inverter fluid to top off the reservoir, and popped the battery in again. When I started up the car, the same thing happened. Said warning lights came on, motor shut off. And the noise that I was talking about, the squeal with variations in pitch and level, seems to be coming from the engine itself, not the inverter. So, after a series of starts and shut offs, I reset my Prius again. When I looked close in the reservoir, I did see the fluid kind of spinning in a circle. Is this what it should do? Curious, I popped a tube on the passenger side inverter bleeder, ran the tube into the reservoir, and opened the bleeder up. Nothing happened. So, I tried the driver side bleeder. A bunch of air came out, with it eventually stabilizing, and no air. When I opened up the driver side bleeder, the fluid in the reservoir increased dramatically, by about one inch. After alternating between the passenger side bleeder valves and the driver side bleeder valves, I got the same results each time. Passenger side: nothing, and driver side: air bubbles at first and then solid liquid coming through. After doing this a few times, the reservoir level dropped slightly, by about a 1/4 inch perhaps. Thoughts?

Dealer quoted me $270 for batter, and $50 for install kit. Some online outfits had them around $150 for OEM battery..

 

Skip to 1:10.

My reservoir definitely does not have nearly the turbulence as the reservoir in the above video. Mine is only swirling slowly, similar to water in a glass that has been moved in a circular manner. There is not much movement going on.