My main battery is designated as "bad". Definitely self discharges. The Prius has sat in the drive for about a week. I wanted to move the car in the drive, but it won't give me a "ready" light. Is this to be expected from a what might be a really discharged main battery? The 12v measures 12.5 off and 11.5 in ign mode. I have the rebuilder coming tomorrow, want to make sure I don't have a secondary problem that's going to make his job hard. Jay W
This does not sound like a traction battery problem. 11.5 is too low, it sounds like your 12 v battery is the culprit.
Don't waste your money on a rebuilder, just buy a new 12v optima for $150. Who told you it was a bad main battery?
The main battery is dead, failed with all the signs, codes, limps, ect and measures bad. It's been sitting for two weeks, most of that with the 12v disconnected. Now that I've set up an appointment, I wanted to reposition the car in the driveway, but car won't get into drive. Its very possible the main battery has self discharged below any "minimums". Would this be a cause of the no start? Or do I have secondary problem? Jay W
Something weird here. 12.5 is not bad, but 11.5 in "ign mode", what is that? You say you can't start the car.
It won't go to ready, just to an ignition type mode (like if you don't step on the pedal and press start twice). The will shift to N or P, but not D or R. I've read elsewhere these are stellar numbers, but not in the bad range yet for the 12v. Jay W
For some reason my code reader isn't getting any codes. The code reader lights up. I can't remember all the lights, but at least the triangle and check engine and brake. I'm thinking now, since it's the main battery that acts as a "starter" to the ICE, if it's dead enough the car might not even try to get Ready. Jay W
You could be wasting a lot of money rebuilding a battery that is not at fault. You would want to find the real problem with a proper code reader. You shouldn't be guessing when it comes to really expensive repairs
Try jumpstarting, either with a car or a jump pack, just to see if it's the 12 volt? Somehow I think this isn't going to change things, but who knows.
Let's assume that the 12V aux battery is still charged enough to get your Gen 2 Prius into ACC mode. To get into ACC mode - foot off the brake pedal and two presses of the power button. If the 12V has enough charge, you should be able to see the HV battery state of charge display on the MFD. What does it show? Do you see at least one pink bar or is it completely blank? The Gen 2 Prius allows you to do several things while in the ACC mode. You can move the power windows, listen to the radio, and turn on the A/C. The A/C runs off of the HV battery so if your A/C is working then the HV battery must have enough charge in it and there's something else wrong that's causing your no READY condition. Please do this before the rebulider shows up. And put a smart charger on the 12V so you don't accidentally discharge it while troubleshooting the problem.
Okay, I wasn't all that clear trying to be brief. The main battery was definitely bad a while ago. Codes, measurements, everything. In messing with the main battery I disconnected the 12v. Eventually I decided I would have the main battery core swapped. I wanted to move the car in the diveway, attached the 12v and got no start. I've been playing with it for a day trying to get the start. The rebuilder showed up, couldn't get the codes either, but had the sense I didn't and disconnected/reconnected the 12v battery again. Everything return to prior. Engine started in limp mode and a the bad main battery codes came through again. It appears I was simply E-stuck and needed to reset the 12v system again, for some reason I didn't think of that. Anyways, good installer. $500+$100travel and core. 6 month warranty. First 80miles has gone well. Jay W
Oh you left out the detail you messed with the main battery. You probably couldn't start it because you didn't lock the interlock switch properly. After the rebuilder came, he locked out and started your car
Not that it matters to the OP now, but just to clarify to get in to ACC mode, you press the power button once with your foot off the brake. When you press the power button twice with your foot off the brake, you get into IG-ON mode. Therefore the things you can do as outlined: is in IG-ON mode not ACC.
Fair enough. Is IG-ON instead of ACC - but the procedure getting to the functions I described was correct.
That was in my first draft. But I'm used to dealing with millennials who can't read past 3 sentences so trimmed it down. BTW, the service plug was properly in. Thanks for the attempted help everyone, 120 miles now, MPGs seem to be climbing. Getting a little better than before the fail now. Jay W
That is good news Jay. Out of curiosity how many miles did your old traction battery have on it? $600 is a great price on a rebuild if it holds up for the long haul.
