It will soon throw a red triangle of death on the dash and go into limp mode. It will throw a ground fault nag. One or more battery modules have cracked leaking electrolyte. New battery time.
It's possible it's just one of 28 modules that leaks and can easily be replaced with one of similar age and health... These are often caused by too much heat. Perhaps your hybrid battery cooling fan needs cleaning? First step is to pull that pack out and clean everything, replace corroded nuts and bus bars and voltage sensors and find out ho many modules are leaking.
How would one determine if it was big or small? Would it be by the number of modules, or by the number of DTCs, or something else?
A couple modules are leaking where stud enters the cell. Just spread around some baking soda, no codes or triangle yet.
While that's the most common place to notice the leak, it doesn't mean that it's the exact location. If I were you I'd pull the pack and deep clean everything, replace bus bars, voltage sensor harness and nuts so you'll have an easier time detecting the location of the leak. Because there's no ground fault error code, if you're lucky the leak was NOT from a crack in the base of the module where the stud enters but instead from where the bus bars connect which could of been caused by a single over-heating event and if you keep don't have anymore overheating events you'll be good for a while. Check you hybrid battery cooling fan, when that gets clogged that's when things heat up. You'll be in the clear if there's no more signs of leaking this coming Summer.
That's kinda harsh... I've played the battery game. I drive my prius long distances. I need daily reliability especially when hundreds or thousands of miles from home often.
One person false sense of reliability, is another person's sense of throwing the baby out with the bath water... And with 2/3 of US citizens having less than a $1K in emergency savings, rebuilding a pack is often the only option they can afford.
If you just have some greenish looking fluid on the sides of the modules, just clean it up a bit and roll on. It'll let you know if it ever really needs work done on it. A HV isolation fault will not leave you stranded, as it will let you continue to drive even after triggered (until you turn the car off). Once you turn the car off, it won't let you go ready again unless you reset the code (disconnect the battery)
Yes, what he said... The leak most likely was a one time event when things were hot... If the leak was coming from below it would likely be something that you'd need to address. So you lucked out for now!
Thanks! I carry a paperclip and an obd reader/eraser along with a 10mm wrench wherever I go. I did rememove the bussbars and soak them in vinegar, then reinstalled. No problems so far.
