No READY light, no errors (P0000), replaced LV battery already

Everything here points to the low voltage (LV) battery... The car sat for 2 weeks while I was on away. I drove it once since then and then I hoped into the car a day later to go to the store. No love. I've had the car for 5 years since new so, yes, I know about putting your foot on the brake!

I originally thought it was the LV battery because I had never replaced it (again, 2012, so 5 years old). Plus, my LV was showing as about 11.7V on the Service Test mode of the MFD. As such, I installed a new Optima battery. I still am not able to get the READY light. I can only switch to Neutral. If I try to go to FWD or REV, the PARK indicator on the display flashes and the car beeps. Several other lights are illuminated too (Brake (regardless of whether or not the E-Brake is on), Hybrid system warning, check engine, etc).

I externally charged the new Optima, tested the voltage through the MFD and everything looks fine. I get 12.5V or so. I never see the HV battery kick in which would raise the LV bus voltage to 13V (plus)... I've also tried to jump start the car using the approved approach (positive bar in the fuse block).

Brake light switch is also OK. The START key toggles GREEN/ORAGE when I depress the pedal and the brake lights also respond correctly.

As mentioned, I periodically see the READY light flash on for maybe a quarter of a second. When that occurs, I correspondingly hear relay(s) click on (and off) in the HV battery enclosure.... That is very brief and is a bit unpredictable whether or not I see/hear this event.

I've hooked an OBD2 reader (ELM327 running the demo version of OBD2 Facile on OSX). In diagnostic mode, I see no errors (P0000) recorded. I've pulled and reset the HV plug although it has never been touched before (no accidents, etc). I have also removed the battery terminals for a minute to do a complete cold restart (i.e. no parasitic 9V battery installed to keep memory alive, etc).

I think that is about all I can add at this point. I'm at a total loss. The dealer said it all sounds like a LV battery issue but I replaced that, as noted. They want $190 to look at the car and I would have to get the car towed there (another $250) to boot. The timing couldn't be worse as I lost my job 1 month ago, but that is another matter.

I can't see that I've missed any steps but if anyone has an idea, please let me know. I really really really don't want to have to send this car to the dealer. I have visions of a $3500 HV inverter replacement which is crazy on a car that only has 53K on it. Maybe that is covered on a different warranty in CA (think the hybrid drive is separate) but even if it is, I still would have to pay almost $500 just to get the car to the dealer. If I can avoid that, it would be great.

All suggestions are *greatly* appreciated!

 

Thanks Bisco:
The OBD2 Facile software does seem to have some semblance of the car, meaning that it asks the brand (Toyota) and then presents two different types of options for the ECU (hybrid and gas). I tried both subsets and neither reported an error. I can't attest to whether or not the ELM327 and software is actually reading all the codes though. It likely isn't as good as a $2000 Toyota approved scanner, I agree.

Can you clarify the "trust your testing methodology"? The testing was really an evolutionary thing. If there is a specific set of steps I should tackle then I definitely would be willing to do those.

I agree on the built in service measurement on the MFD. Let me clarify that a bit... I also thought 12.5V was a bit on the low side for a lead acid 12V battery. On a $500 Fluke 289 (I work on electronics, although not lead acid or car based stuff), I'm reading 12.75V with the car "OFF". When I press the START button (twice), it drops to 12.375V and the MFD reads 12.2V. All of these seem lower than I would have expected, frankly, and one thought I had/have is that my brand new (3/17 date code) Optima battery may be defective. That seems rather unlikely but????

The Toyota dealer said, interestingly, that the ready light should come on with the LV all the way down to 8.75V. Honestly, that seemed *really* low to me and also completely contradicts almost everything that I have read within forums on the net. I don't place much credence in that number as a result.

Again, thank you for your thoughts!

 

I see this: Ogrmar Mini VCI Car OBD Diagnostic Scanner OBD2 USB Interface Scan Tool for TOYOTA TIS on Amazon Prime. I assume this is what you are talking about? If so, does it come with the software that will allow me to read the full set of codes [edit: never mind... I see that one needs to obtain that separately]? The reviews seem to be a little iffy on that one.

The battery date code on the Optima is 317 (so, March 2017, I assume). I bought that battery from Pep Boys yesterday. There are enough Prius' in California (Bay Area) that I assume it is a pretty fresh battery. I had it sitting on a trickle (2A) charger for about 4 hours yesterday too.

The interesting thing here is that I've also tried the jump start battery which has managed to crank over my Honda Odyssey (about 7 months ago). I full charged that buck battery before trying it on the Prius. I've also tried installing the old battery (after it was charged overnight and showed about 13.x volts. Everything ends up with an MFD voltage in the low to mid 12 volts (12.2 to 12.5). It is almost as though there is a load. I actually have a current clamp so maybe I'll check that out.

Everything seems to point to the LV battery but I can't seem to pin a specific cause/explanation here. It is pretty frustrating.

Oh, on the chance it could be some other innocuous thing, I did check each and every fuse that I could find in the block. There was nothing amiss there. There is one large beige box on the left (facing the car from the bumper) labelled P/I (I recall). I think that is a relay but I'm not too sure. Whatever the case, there are two holes marked I and O (again recollection here) that look to be LEDs. I can't get anything to light, however. I'm not sure if any of that is significant.

 

Bisco:
Yes, the brake lights come on when I depress the pedal. The START button also changes from ORANGE to GREEN as a function of the brake pedal's position too. So, unless there is an additional sensor/switch on the pedal, I think I'm probably OK with the brake part of the startup sequence.

Air_Boss:
No, it is a straight charger without any advanced functions. The unit is fairly old. I wouldn't expect that I would need a conditioner, however, on a fresh battery that has a date code of 3/17. There should be nominal oxidation of the plates in only 2 months or so.

JerryMildred:
OK, thank you for reviewing the OBD2 Facile site. I'm pretty green on what one needs on an OBD reader for a Prius. I ordered the Mini VCI referenced in my third post. It is arriving today. Unfortunately, when I lost my job I also lost my VM with XP/Win7. I have a VM on my main computer but I don't have the VMWare app on a MacBook and, well, without a job I'm hesitant to buy a new VMWare copy now. However, I *do* have an ancient XP laptop (got to find the power cord) as well as a Linux laptop. What software package(s) are you running on your XP and Linux machines? I'll try to install those. I get the feeling that Techstream is a grey market download that probably only works on a PC (?).

Pardon my ignorance, but can you clarify the definition of PID? To my engineering side of the brain, that is 'proportional, integral, derivative' control speak... But I know you don't mean that... ARe you referring to the Pxxxx definitions (as in the error codes that show up when you list the errors)?

Thanks to all for your help! I really appreciate it!

[edit: added b/c there were additional comments while I was responding]
I considered that I may have been compounding problems. That is always a concern when running somewhat blind. The HV plug removal was as follows: slide bar to left, rotate handle backwards, pull... The insertion was the complete opposite, INCLUDING the sliding of the bar to the right again. I think that is correct. I also examined the contacts on the interlock plug and they look shinny. Also, I believe a missing interlock will result in a Pxxxx code, doesn't it? I don't see any codes on my ELM327 (granted, there is some discussion on whether or not the device will show all faults). Although I'm not 100% confident of anything at this point, I'm pretty sure the interlock is fine. I guess I could video this an upload though if you think it will help.

 

Bicso: Good suggestion. I've used YouTube extensively but for this particular disconnect I thought it was pretty basic so I neglected to confirm there. Anyhow, I just reviewed this:

I'm doing everything properly. If what is shown in the video is the complete number of steps (can't see much else that could be done) then I'm doing all of that.

 

In desperation, i have tried to jump start the car again (using the fuse block positive). I looked at the MFD voltage and it is reading 13.1V but drops to 12.9V periodically again. At any rate, the behavior is identical to before. The READY light doesn't come on (and a lot of other warning lights stay lit), and although I can move the shifter to Neutral, the PARK indicator starts flashing, etc. I can't move to DRIVE or REV.

I'm beginning to wonder if maybe the Inverter isn't getting power.... Is there a fuse between the HV battery and the inverter? Is it worth taking the top (black) plate off of the inverter and testing the input leads to see if they actually have 2xx volts? I'm an electrical engineer (but *not* automotive) so I've got good understanding of voltage, current, etc. That said, I don't want to open the inverter if this is a fools errand that won't net any useful information.

Alan

 

Jerry:
OK, I assumed that PID was the ID but wasn't 100% sure. The reason for the confusion was this, though. I can see that a set of PIDs may change from car to car, but I would have expected the basic PID information (P0001, P1223, P4344, etc) to always be reported though. What might be missing would be the dictionary, if you will, that translated P0001 to mean 'Oxygen sensor short' or some other human readable message...

If the Pxxxx codes are presented to the user (in my case, the ELM327 with OBD2 Facile) but without translation, that would be OK. At least I would know there was an error code I had to research. However, in my case, I am getting a report that indicates there are no error codes at all.

As such, the question remains as to whether or not the inability to upload/configure the OBD hardware/software really matters. It might be moot because I've already ordered the recommended hardware that you guys were talking about. It should be here today (sometime) but I'm wondering if I'll actually see new errors that were not previously reported. Frankly, at this juncture I'm kind of hoping I do. I'm flat out of ideas now and that is a very uncomfortable place to be. <sigh>

Thank you for the help, though. As always, it is greatly appreciated.

Regards,
Alan

 

Bisco:
The 12V LV battery replacement is pretty straight-forward, unless I'm missing something (I never claim to be an expert... rule #1 in my book). The ground strap side is at the rear and is tight (confirmed at both the terminal and the bond to the car). The positive side has a right angle connector but all of that is tight too. On top of the hold down bracket there is some type of connection that I didn't remove. I don't know what that is but given that it is attached to the strap with a simple plastic clip, I am assuming the block must be a temperature sensor or something. Toyota clearly wanted the block to be positioned there. I didn't remove or pull hard on the wires there so I think I should be fine.

<sigh> it looks like the dealer might end up being my last option pretty soon. You guys have been great with suggestions and ideas but so far everything seems to be installed correctly, etc. Bummer.