The red triangle of death..

late in 2010, I got a great price on a 'new to me' 2007 Prius. With 92200 on the 'clock' I decided to give it a try. It was not long before I grew to really love this car. Fuel mileage is great and it has been a fun car to drive. Thanks to the Prius chat forums and other internet sites, I have installed the 'missing' EV switch to allow stealth operation. Also of great help was learning the 'dance' required with the foot & shifter to disable the traction control. Recently though, the car has displayed the red warning triangle with a few other lights. Having been an ASE master auto technician since 1981, this vehicle has been quite a learning experience for me the last 8 days. Naturally for me, when a light comes on, I need to know what's up right away. Investigation found a code in the computer for a failing cell block in the Hybrid battery... wouldn't ya know it.. the battery is warrantied from Toyota for 8 years or 150,000.... and of course, I had 154, 213 when the light came on... I've given the Toyota Hotline a call, they were quite helpful, took all my info, and told me that I would need to visit a dealer for an official diagnosis. Having been in the industry for years, I get that.. The story to share though, is how quickly things deteriorate as the battery goes south. The day the triangle lit up, with it came the yellow VSC light, the yellow brake warning light and the check engine light. The computer shuts you out of the ability to use the cruise control, and the top 1/2 inch of the information display is changed to show an outline car, in red, with an exclamation mark inside. "Ok, the car still runs & drives, but no cruise control" I thought to myself, knowing I was to make a 280 mile trip over the next 2 days. So I cleared the codes from the computer thinking "let's see how far I'll get before this thing re-codes" .... Things were good for the next day or so, I got 130 miles of my trip with the cruise. ...then with a little jolt as the cruise shut off, I heard the 3 little beeps, as when the 'Add Fuel' message comes on, but this time the text shown was "PROBLEM".. I had to laugh out loud upon seeing that. Once again the dash is all lit up. So, I think to my self, I'm gonna need to get this looked at sooner than later. I tried clearing the computers mind again. This time, It was not even an hour before all the lights came back. An appointment was made with Toyota, 5 days away. My trip to work is 40 minutes or so... as I'm making the trip, with the Toyota visit now 3 days away, I roll into the throttle as I'm going up a steep grade, as I feel what tries to be a downshift, the car bucks, engine revs higher with almost no power... 3 more beeps and the 'PROBLEM' text again. Now next to the little red car with the exclamation point, is a little red battery symbol. The engine has not stopped racing, the car has virtually no throttle response. I pull over, shut the system off, wait 5 seconds and restart. ...was able to continue to work. Over the next few trips, the car would do the high rev, no power thing as I stepped too much on the throttle. It also did it a couple times on long down hill grades. (Now 7 days & 2000 miles after seeing the warning lights for the 1st time) The time arrives to see the dealer. I had chosen the dealer where I purchased the car, as it was also close to my folks home, where I might borrow one of their cars if needed. This dealer though is almost a 2 hour ride from home... leaving after dark for an early AM appointment, I hit the road... 1/2 hour into my trip, I hear that now all too familiar 3 beeps.. Now, the information display shows the red battery icon, the red car icon, and another red battery icon with the work MAIN inside. The engine does it's high rev thing.. As I'm moving 65 down the highway, this is not good... I'm going down a hill and know of a rest area a mile away.. so I'll just see what happens... the information display now showing the "engine, battery, and electric motor power flow" lights up, or should I say 'un-lights' all power flow indicators have gone off... there is now a constant beeping the drive "D" symbol in the speedometer area had been replaced with "N" ... The info display now has a message something to the effect of ... "there is a problem with the park mechanism, stop the vehicle and apply the parking brake"... The engine can be heard running, but there is no throttle response at all.. the head lamps are now at 1/2 brightness... I hit the 4 way flashers and coast into the rest area... As I stop the car and shut it off, the dome lamp comes on as expected but very dimly. I attempt to power on, but only dim dash lights. I shut off all light switches, waited a minute and tried again... System ON... . Was able to move again... Got to a safe spot to call AAA for a tow, seems they are having a busy night and suggest a 2 hour wait... Ok, I'll take my chances.. I made it to my destination 100 miles away.. I did have to stop and reboot the system 4 times.. But I did learn that when the high rev thing happens, pull over soon and reboot. .... The best news is I just had Toyota's service adviser chat with me.. They have made their official diagnosis, find that the car needs a battery. They are asking that I pay the $375 labor fee, they will buy the $3000 battery...

 

Yes, the delay was on me due to a very busy work load this time of year. The light had first come on Monday Nov 12 as I was leaving work, the following day, I got in touch with Toyota Hotline and the dealer. The dealer had space on their appointment schedule to get me in, but my schedule would have me tied up till Nov 21. I must say as a technician, having put over 60k on this car, it had been an interesting learning experience to drive the car with a failing main battery. I have driven many different vehicles with many different ailments since 1978. Certain vehicles can continue to be operated with some of the issues that arise, and for some time at that.. The Prius too, can run on the gasoline engine when the battery is failing, to a point.. The transaxle and it's controlling computers clearly need certain voltages to continue to operate properly. It seems to me that the designers of the Prius and all the controlling computers were designed well to get every bit out of the battery before the warning lights come on. Once they do, based on my experience, one has about a 2000 miles of traveling before the car will 'tell' the driver, "that's it, I'm done"...

 

I know that my 12v battery was weak, I actually had just purchased the replacement the day the warning lights came on. I must admit a bit of confusion about the headlights dimming though. My guess is that at some point the computer shut off the hybrid system, and in doing so, shut off the 12v battery circuit to the headlamps. I'm speculating that the engine still turning as I was slowing to a stop, was generating some power to keep them on.

 

No insult taken at all. No, I would not have advised a customer to continue driving. I must admit that over the years, I have done a bit of failure analysis, both on things I've seen come into the shop in a failed state, and on some of the vehicles that I've owned as problems have come up. I must admit, when the battery failure light first came on, I was concerned about replacement costs as I knew the warranty mileage had passed. A Toyota service writer / friend of mine, suggested that I give the Toyota hotline a call, suggesting that he had seen Toyota helpful in other 'just out of warranty' situations. Which I did. As time went on, knowing that I did have an appointment with Toyota, I absolutely did 'test' the limits of what the car would and would not do in it's condition. At this point, I feel good to have had 1st hand experience with these issues. At this point, if a customer came to me with a Prius with a failing battery code, I could tell them from my experience that it is a condition that must be attended to ASAP. I understand when folks are given troubling news regarding their cars, they sometimes wonder 'How long do I have', or, "How much will this cost", "do I have any other options". I would be comfortable answering all those questions and would be able to let them know what to expect if they 'had to' continue to use their car for a while before repairs could be made.

 

I admit being aware of the inverter charging the 12v battery. I have a set of fog lamps wired in directly to the battery, (hanging my head in shame..) and yes, I've left the lights on to the point of needing a boost to the 12v system to get the car running.. What I'm not certain of is how the electronics is wired/controlled. As I think on what happened, I'm suspecting you may be correct, in that the 12v battery was not being charged as I was coasting to a safe stopping place. As I stopped after the lights went dim, I did have to wait a minute or so before the power button would respond properly and reboot the 'hybrid system'. At that time the dome lamp did come back to full brightness as the inverter clearly started its 'charging output'

 

Just as a follow up, the car was droped off at Toyota the day before Thanksgiving. From what I understand, the new battery was ordered 'overnight' so that it would be there to be installed Friday. Sure enough, I got a call mid afternoon Friday to let me know the job was done. The car runs and drives 'like new' as I would expect. I'll be installing the new 12v battery this weekend. I had purchased it the day before all the warning lights had come on..
It has been suggested to me that I may see an improvement in MPG by replacing a weak 12v battery, as the hybrid system will not be doing as much work trying to charge a failing battery. I'll post an update as I watch things over the next few weeks. ...I must say though at this point, that I have seen a difference in the 'state of charge' indicator for the hybrid battery. I live in the Monadnock region on NH, which does have some very hilly roads. With the information display showing me the 'power flow', I've noticed over the last few months (before the warning lamps) that the 'state of charge' indicator would fluctuate from high to low more quickly as I would travel up one particular mountain road. Conversely, I'd find that it would indicate a 'full' recharge by the time I had gone down the other side of the mountain. When I first started noticing this trend, I did not think too much about it. I guess I was writing it off mentally thinking it was colder temps, and the use of the winter blend of fuel that we get around here. Clearly though, it had to do with the batteries inability to take a proper charge. With the new battery in place, I can go up the mountain without the indicator going down to the purple bars, and it's not 'full green' at the bottom. .. I'll post more when there is more to report..