Auxillary Mullet, please help

Hello all,

Like so many others, I have been appreciating your help from the shadows, but today I step into the light with an issue I haven't seen anywhere else, seeking an answer to 2 dumb questions.

2008 Prius hatchback, 2nd owner (2015), 176.6k miles. Carfax showed no accidents or damage, it's not a salvage nor rebuilt, odometer wasn't found to have been tampered with, etc.

This is very long, but I want to include everything in case one thing caused another, or will rule something out, etc.

I bought a new 12V January, but didn't have time to install it until the middle of Feb. I did charge it before the install. About 6 weeks later I began to experience the car randomly not starting. It would be completely void of power, clock, windows, and stereo reset themselves. Though sometimes I would notice that the clock reset, but not the stereo or windows. Anyway, sometimes I just had to wait a few mins and it would start right up. Other times, I'd open the back passenger side door and all the lights would come back on and when I tired to start it, it would start right up or die. I took the battery to be tested, it tested fine.

It'd be fine for a week or two, sometimes a month, then it'd happen again. It wasn't throwing any codes, but it was resetting itself, so of course it wasn't (I have techstream). Sometimes I'd hit the panel above the 12V and all the lights would come on and it'd start or die. I'd climb out of the hatchback and the lights would come on and it'd start or die. I'd jiggled the wires from the positive terminal and the lights would come on and it'd start or die. This was intermittent and there was no pattern as to when it would happen or as to how many times it would take to get the car going each time. It came in waves, meaning when it did happen, it was frequent for a few days, a week, 2 weeks or so. Sometimes it'd happen a few times a day, sometimes once, and sometimes (as noted) not at all.

It would successfully jump start (every time), which I know isn't good (can't recall why), so I'd only do if I needed to be somewhere extremely important and none of my fiddling worked in a reasonable time frame. I'd say it's been jumped far too many times (10?), with a portable pack I keep for emergencies (only used it to help other folks until this year). During this time, I have taken the battery (which is under warranty) to be tested several times. Each time it showed no signs of failure, and I wondered if the battery could have an intermittent issue that would fail the test only if it happened during the testing. I also know it could be a bad/loose connection somewhere. I had been scouring the internet seeking a resolution to this issue, but couldn't find one. Eventually I found a thread of a person having a similar issue, and a member had suggested something I can't recall and ending with unless you want to get really long cables and connect the 12V to the jump point (paraphrased). I'm not sure if this was in jest or not, but I happen to have very long jumper cables and decided to give it a shot. Started right up, and did so numerous times. Okay, it's connection issue, but with a new symptom to search. I then came across another post where someone described the no starting issue, but discovered when getting ready to jump the car, that the power returned to the car only connected the clamp at the jump point to the negative terminal - without power. So I tried that, but by the time I did the test, I tested the positive terminal (not realizing I had mixed up what that user reported until I double checked afterward), and sure enough the power returned to the car and it started right up. I can't find either thread now, or I'd post links. I performed these tests only when the car would die, and it worked, but obviously there's still an issue. I can't recall the solution for that individual with 100% certainty, but I think it was a new 12V, so I had mine tested again - it passed. Bad connection/bad 12V had now been screaming at me for months.

Now, I want to note that when I changed the battery in Feb., I discovered that water issue that I learned was fairly common with this generation prius. I dried everything out and sealed the hatch with RTV and that solved the problem. When I thought about that, I decided to start my connection search in the back and removed the panels out of the hatchback and inspected for corrosion on the connections where the water had been coming in. I did find one connector with a bit of corrosion and removed it with vinegar, let it dry thoroughly, then reconnected. The car started without issue for about 6 weeks over the summer, so I thought I had solved the problem. Nope. The problem came back.

During the time I had deemed the problem solved, (stay with me here, I promise it's connected) I decided it was time for regular and preventative maintenance. I was due for an oil change and there was nothing on the service record about a transaxle fluid change, so I figured I'd do it while I was already under the car (it was very dark, I suspect it hadn't been done for the life of the car, but strained it and didn't find any metal). I felt it was a good idea to change the inverter coolant pump as, according to the service record, was last done approx 91,700 miles ago. Nothing noted in the service record regarding a coolant change. The engine water pump was changed approx 117,500 miles ago, and nothing noted about a coolant change. Both noted SLLC, but I know they could have drained and refilled with the same coolant. I decided to replace the coolant on both systems and the parts too, the water pump didn't show any signs of leakage, but I figured why the heck not. Figured it was a good idea to change the thermostat while I was in there.

I can tell you with certainty that something else was done on this car, because when I drained the engine coolant it was the red stuff. Not in the service record, but doesn't need to be. So that makes me question what else could have been done that wasn't on the carfax/service record, but I've no way of telling.

Anyway, I already had the parts and fluids so I decided to do the work anyway. I started with the oil and atfws fluid change. Decided the engine water pump and thermostat change should be next as the car was already up on jack stands (4 of them). I drained the coolant, removed the parts, and called it a night as it was dark out by that time, saw no reason it couldn't wait until morning. Well, wouldn't ya know that night I smashed my hand in an unrelated incident. Nothing broken, but I did sprain my index finger and that wouldn't have been such an issue had it not been for the work I was in the middle of doing. Now, I have a splint on the index finger of my prominent hand. I, stupidly, went to finish the job anyhow. After all, it's just gaskets and hardware, right? Wrong. I ended up needing to do the work with my left hand, since I couldn't get into such a tight area with a splint on my finger. It was no easy task, but I was pretty happy with myself when I got the parts on, until I began to pour in the coolant and it immediately spilled to the ground. One of the gaskets didn't seal. I had failed to ensure that both contact points were clean before putting the pump on. That's what I get for changing a part that didn't need changing. I removed the pump and scraped both sides, ensured it was clean and dry, then put it back on. Same thing, lost another qt of coolant (that's 1/2 gallon at this point). I didn't want to take it to the dealership, but I definitely didn't want anyone not experienced with hybrids to bleed this system. I knew that the issue was likely that I didn't have it on tight enough, I couldn't maneuver my socket or torque wrench well, given the small amount of space and my temporary handicap. Ultimately, I called in a friend of a friend (mechanic), and asked if he'd be willing to look at a hybrid, but forget about what he knows about working on regular cars. I explained the job and why he shouldn't assume bleeding this is the same as any other car. He was agreeable, and he had asked enough questions as I went over the process, that I felt that he had listened and would complete the job as instructed. Our schedules didn't really line up, but I left everything out for him to take care of it while I was at work, which made me extremely nervous, but I needed my car back. Sharing a vehicle when we both (myself and my other half) work couldn't continue.

He was still there when I got home and the work was about done, and it wasn't too much longer that the coolant was flowing air bubble free from the bleeder to my funnel (Lisle - I'm not one to advertise, but if you DIY cars - get one, it's worth every penny). He turned the car off, and I was happy that it was done. The inverter pump was just going to have to wait. We chatted a bit as he was curious about the car. He noted the absence of a 12V and alternator, so I showed him the 12V and explained that there wasn't an alternator. And before I could mention the odd problem I was having with it, he noticed something I never did. The post on the positive terminal was too short, and the connector being taller than it, was only connected on the bottom (facepalm). How could I have missed such a blatantly obvious thing?! I had repeatedly removed that battery! He pulled the post up and reconnected the terminal and I couldn't have been happier about my dumb luck. So happy that I wasted money on a pump and that I was injured at an extremely inconvenient time (never thought I'd say that). I topped off the radiator the next morning, and it started up without issue, but the check engine light came on. I figured it was the result of all the stuff that I had been doing to it in the days prior, and figured I'd see how it drove for a few miles before I went to work (because I'm an idiot and because my other half had left with the other car and I didn't want to be late for work). It ran without issue so I drove the 50 miles to work, no issue. I topped it off again after my shift and thought that it took an awful lot of coolant considering it had just been filled and topped off this morning.Now, when I removed the under covers, a fair amount of hardware had been rusted/corroded and broke upon removal. I planned on ordering new hardware and reinstalling when it arrived . Because of this, I was able to see the coolant tank from behind the wheel and discovered that it hadn't been plugged back in. I had forgotten to mention it to the mechanic and was so happy about the battery that I assumed it was done properly and hadn't checked (stupid). I was able to reach to plug it back in, and had the remainder of the coolant in the back (which I also hadn't checked - dumb), so I went to work filling the rest and bleeding it in the parking lot at work. Now I know why the check engine light was on, but why did it drive without issue without the coolant? Luckily, Toyota was prepared for my daftness and implemented a fail safe. I drove it home, again without issue, and ran techstream when I arrived home. I can't recall now which codes it pulled, but I cleared them and drove around for a bit (city and highway), and they didn't return. I topped off the coolant as needed until it didn't need to be topped off anymore, and checked techstream periodically during that time. No lights or codes returned. A few weeks later, I changed the inverter pump and coolant without issue.

That being said, I began to consider the traction battery as I had been doing all of this work/had work done (had replaced the cat, muffler and related sensors the year before last) and it'd all be for naught should the HV battery fail. After doing some research, I learned that it was showing signs that it was on its way out (from purple to green in just a few minutes). It hadn't been throwing any codes, so I decided that it was a good candidate for the Hybrid Automotive reconditioning system. It arrived about a month after engine coolant conundrum, and I haven't had time to recondition it, but did do an overnight charging. Just in time for a long weekend away, and I put about 350 miles on it without issue.

When we got back, I wanted to take a look at the battery blocks in action, so I plugged in the blutooth obd2 reader and connected torque pro. Everything seemed okay, but about 30 miles in (with a few stops in between) the VSC, ABS, and brake system warning lights came across the dash. My connection to torque pro had been lost when I received a phone call, and I was unable to run the test for DTC. So I pulled over and shut the car off. Turned it back on, and the lights went off and no codes were found. I was about 20 miles from home, so I cautiously drove home, and didn't really note any difference in the brakes. When I got the car, I had new brake pads put on the front and shoes on the back, but that's all I've ever had done in regard to brakes. I ran techstream when I got home and pulled DTC's u0123, u0124, u0126 - all communication issues with the skid control ecu. I did drive about 30 miles (city/highway) to see if the lights came back on or it it threw more DTC's, it didn't. After some research, I discovered that running the app while driving can cause communication issues and throw those codes, but I started troubleshooting anyhow as I'm not taking any chances with my brakes. This was about a week ago, and this is my 4th day troubleshooting. I wanted to study the manual (which I downloaded from TIS, but not in its entirety before my 2 days were up - I do have CANbus stuff), and located a copy of the wiring diagrams.

First thing I did was check the 12V, I checked at the jump point, the readings were all over the place. The voltage starts low and then jumps all over the place until it settles, usually on a low number. I've seen it lower than 1V, around 2, 5, 8 etc. I immediately went to the battery itself and it read at 12.68, and when I went back to the jump point, it read around 12.4. And I checked it after it sat for a few hours, with the same results. Check the next day, same thing. So it's low in the front, high in the back, and very uncool (it's a mullet). The car started without issue (as it had been since the battery post adjustment), and the 12V jumped to 13.8V when the car was running. I followed the trouble shooting steps for the CANbus until I hit the road block of my techstream not supporting k-line. The DLC3 read within specs, I proceeded to the skid control ecu, due to the DTC's that had been thrown. I had written down which connections, numbers, and what the resulting values should be as I didn't want to bring my laptop out to the car and didn't want to print multiple pages (wish I did), then began to troubleshoot with said instructions. By nightfall, I still hadn't reached the S8 and S9 connections, I spent the day removing the dashboard (there has GOT to be an easier way), and located them in the morning. I had a heck of a time getting something small enough to fit into those connectors to measure the ohms (that was another half day project).* When I finally got the measurements, they were within specs.

So now my dashboard is completely removed, and I'm not going anywhere (see footnote). Since I have the 12V disconnected and don't know how long this will take, I put a trickle charge on it (wish I started the reconditioning of the traction battery). At this point, I went back to the manual to get where the other ecu check points would be and what resistance measurement I should be looking for, and that's when I realized that I missed something important when I wrote out the instructions (I am so daft). Disconnecting and Reconnecting J15/C1 and J18/C2, so my measurements have been off! Also, I had used the leads to measure at the DLC3 and considered that the measurements might be different if I had used a service wire. Now I have to retake the measurements, which is no big deal as the dash is still apart, but I if my life depended on identifying which connectors I need to remove/replace to do this, I'd be dead. I have been pouring over the wiring diagrams, and I'm so lost on this. I note the part location, then it doesn't line up - there's nothing there. I tried looking up the type of connector I'm looking for, but J15 and J18 are the same as IJ3, IG3, ID3, IC1, IA2, J31, J33, J19, J14, J9, and J10. No specific colors noted. I noticed that they don't have pin numbers, but letters (A and B), but I can't find any mention of what that means, so it's not helpful. I've been going back and forth from the car to the diagrams and I just can't find it. So my dumb questions are where can I find these and what do they look like? Anything that differentiates them from everything else? The manual says they do, but I am looking at a sea of the same.

I can't just put it back together and call it a day. Somewhere between the jump point and the 12V something isn't right and it's causing my auxiliary mullet. Help?


*My other half is away for work with the other car, so with a torn apart dash, I've got stuff I have on hand to work with. I managed through trial and error to get something to work. I used wire threads to basically tie/connect sewing needles to my leads and I was able to measure that way. This is long enough, so I'm not going to go through all the things that didn't work. I've been taking the remainder of my vacation time at work, but will run out on the 10th, so that's my time crunch

 

I see now that I have provided far more information than necessary. I get long winded when I get overwhelmed. I will edit to a condensed version.

Yes, I'm very concerned about the aux battery, after it plaguing me for so long, I think I should be. I've not been able to find anyone else experiencing that large a difference in Voltage. One day the jump point read 0.48V and the battery read 12.68V. I don't believe that to be normal. @FantasticalMagicOne is correct, that is why I am hesitant to just put it back together. Tearing it all apart again because I didn't do the job thoroughly is not a bridge I want to cross.

@dolj You are not wrong, but when it comes to the brake codes and warning lights, running the app is only one possibility as to what may be happening. I'm not fond of the idea of taking chances with my brakes, and checking for a short is one way to verify their validity, but to each his own.

Perhaps I should have come here first, but I didn't. I comprehend that all of this work may end up being for peace of mind, but the dash is already apart, the work needs to be done regardless. So if I could just get some help identifying these junction blocks?