Red triangle of death won't disappear after new 12V battery

hi all,

After 18 years of service the 12V battery of my 2005 Prius finally gave up. We replaced it with a new one (easy job).

When the battery died, the red trinagle of death appeared, but now it will not disappear. The message on the screen says the problem is the automatic parking brake, but that does not seem to be the problem, the APB is working fine and that message also appeared when the battery was down.

It could be that the new battery is not charged enough for the message to disappear, but that seems a bit strange after driving 30-60 mins for the past three days.

Is there a way to reset the warning?
thnks!

 

I am not able to do a code reading myself, but the triangle showed up at the exact moment of the 12V-battery failure. I have a several mentions linking the 12V-battery issues with the same error message regarding the automatic parking brake.
An, as the car has been driving without issues for the past two weeks i do think the triangle of death's appearance was caused by the battery malfunctioning.

However, how do I get rid of the triangle and the message on the touch-display ? The only advice on this I have found said it would disappear after several thousand of miles....
It would be great if someone could point me to a quicker resolution!

 

Thanks for your response. I did a code read (with dr Prius and Auto Doctor), but no error code came up. No pending, permanent or confirmed errors.

Only at one point, dr Prius briefly gave a B2799 code. But this was gone quite quickly and did not return. Still, the red triangle of death remains with the automatic parking brake warning.

Additionally the past days have seen some electric/electronic oddities: when i shut off the vehicle-system and pull out the keyfob, it sometimes happens that the car remains in On mode (not Ready, but when all electrical systems are active). This even after pulling out the keyfob. I have to shut off the systems several times before it really sticks. Also the clock quite often resets to 1:00 and air temp to 22 degrees celsius during shut off. I would not be surprised if a the keyfob is nearing its enddate, it is quite old and kept alive with duct-tape.

I anybody has any ideas how to get rid of the red warning triangle or the cause or the electronic malfunction please let me know!

 

thanks for your suggestions.
There seems to be a difference between the US and EU models regarding the parking brake. Here we have a manual parking/emergency brake, operated by foot. And there is an automatic parking brake that is applied when the car is put into P. We do not have a button for a parking brake.

There is no issue with the emergency brake, it is working normally.

I have read posts where a faulty 12V battery has led to the same automatic parking brake error message on the display. It seems to be a default message when electrics does not function fully as wanted, i.e. low voltage.

As I have no manual charger and the car cannot be parked next to the house (i live downtown in an apartment), the new battery has not been charged manually yet. I agree that would be the logical next step. It wouldn't surprise me if the battery has been in storage for quite some time and does not load easily (or nog fully at all).

 

Below picture is similar to the warning message that is continuously visible in combinaton with the red triangle.
Thus automatic (P) "transmission lock mechanism" would probably be the best way to refer to it.
Probably needless to say that applying the parking brake does not solve any issue..

 

The strange thing is that the "P" lock mechanism does work normally and always has worked normally. The car does not move in P, even if its parked on a slope.

What I read elsewhere is that a lower voltage can cause the warning: 2005 Prius- Battery went dead- Error reading "transmission lock mechanism abnormal" | PriusChat

My guess at the moment is that the warning was caused when the old/original12V battery was drained and that the new battery I installed is not loading properly. When the electric system is active the battery is charged with 14V, but when the system is off the voltage is never above 12.0 volt, sometimes dropping below 12.

I haven't been able to go by the shop. Apart from the warning and the issue with the key fob, everything seems to be working fine.

Below the OBD2 reading via the Auto Doctor app, you see the 14V charging on the right hand scale (green line) and the battery voltage on the left hand scale (blue line). This is similar to the readings I get when using the Prius check via the display in Vehicle Signal Check Mode (second picture).

 

Finally been able to bring the car to the Toyota workshop, they found the following current codes:

• C2310: Transmission control -> 'open or short circuit in battery circuit'
• C1241: ABS/VSC/TRC -> 'low battery positive voltage or abnormally high battery positive voltage'
• C1256: ABS/VSC/TRC -> 'ACCumulator low pressure'

and a historic code that might be relevant:

• B2796: Immobiliser -> 'No communication in immobiliser system'

additionally, dr Prius finds a B2799 code once in a while -> 'miscommunication between the Engine Immobilizer and the Hybrid Vehicle Control ECU'.

Apart from the red triangle and warning described above, some strange issues occur regularly these days:

1. after shutting down the car and retrieving the key from the system, the car starts up again without the key in the sockety. It is in the ig-off mode then. This only happens once, after pushing down the start/shut button another time it does not happen again.
   • could this be caused by a faulty key?
2. sometimes when the car is not on, all electricity drops, the car does not respond to the key or gives an indication the door is open or anything else. The 12V battery still measures 12.5V, but there is no current in the fusebox. Electricity restores after a couple of minutes without anything happening
3. electricity does not drop during driving, however, each trip, at least once a warning beep sounds without any indicator light on the dashboard coming on.

Given the codes I am still thinking of some 12V circuitry problem, the are beneath the battery is heavily rusted and has a big hole. As the negative pole is connected near that area, could this cause some issues in the 12V current stability?

Any of your thoughts are highly appreciated.

 

Code C2310 lead to P Lock C2310 Fix Fixed Solved Solution | PriusChat which gave the solution: adding a jump wire between "the 7.5 amp "P Con" fuse and this plug next to the positive jump point in the engine bay fuse box. It's the blue wire that leads from the P Con fuse to pin 13 on the Transmission Control Computer." See the video in mentioned post.

The red triangle and P lock warning message disappeared. For now no drop of electricity or unintended restart of the car. Will keep posted if these happen again.

Thanks for all your help!

video of solution by strawbrad | PriusChat
https://inv.vern.cc/embed/r2VOAyOvlxo

 

Unfortunately, not all problems are gone....
The car still loses all electricity at times (luckily not yet while driving, only when it is not yet on). Key fob doesn't work, open doors and doorlights do not work. Clock goes back to 1:00 and temperature to 22 degrees celsius....

Any clues where to look? Could it be in the immobiliser system, an issue with the anti-theft system or still another problem in the 12V circuitry?

 

hi John,
Thanks for your advice. I'll try to find a way to run techstream.

The other recommendations I have already done, hooked up the 12V several times to a charger overnight and and replaced the batteries in the keyfob. Both did not make a difference with regards to the issues.

I have only one keyfob and it has been breaking down where you press it, it is being held together by duct-tape, so I wouldn't be surprised by it causing some issue...