Help ICE wont start, Comm buss Down after Cat stolen/replaced

OK I have downloaded the manual and electrical diagram. I also checked both sides of the ECM fuse today just to be sure power is getting there and past...it is. The manual itself is a bit overwhelming for me. I would love to persist and fix this problem. IF anyone can direct me to a page, or etc. to proceed from, what part of the manual to follow to trouble shoot this ECM down issue, ... this would be a huge help. Also, I wonder if there is a simpler solution or place to look for one we might be missing. I want to remind everyone, that, things got much much worse once I drove it a half mile (and ICE did not start) and had both the 12 volt and the drive battery get low, the synergy drive shut down then, to protect the drive battery... (still 24% left according to Dr. Prius and every blade still measures 7.58 volts...total drive batter voltage 211) DID Something happen in that moment(detailed at top of thread)..of batteries going dead....that shut off the ECM power??? something someone might know about, and how to reset. Since towing it home with neading a jumper box on 12 volt battery to get it into neutral so I could tow it 1000 feet home, and only one other time it went into neutral back in the garage, the car has refused to even shift into neutral, even now with 12 fully charged. ECM seems off line, etc...what could have caused that???...any speculation welcome.

 

Thank you. I have the 2006 manual as a PDF. It is over 5000 pages. I feel overwhelmed by it without support. Can you please direct me to where, or how...even... to find the procedure to trouble shoot my problem please? I assume there are no ideas on a simple solution, some shut down system that could be reset, etc?

 

The manual I have came from another Prius chat thread, found here,How do I change Coolant Temperature Sensor? | PriusChat , but I downloaded it and have it ok. Offered here so you can help coordinate my progress with the same manual?? maybe...I hope

 

Thank you, this is helpful and points my direction. I am starting to see what you mean about the challenge

 

Thank you for this possibility for consideration. If this is the case that the drive battery is so low it would trigger red triangle, then I need to address this, and it could take me a whole different direction than I been going. But I still have the problem of the communication bus being down, and I don't suspect low drive battery, with OK 12 volt battery, which is verified good, would cause this communication bus problem directly of itself. I got the information about the state of the battery from Dr. Prius and acceptable voltages, from the chart at the bottom of this page, Prolong Hybrid Automotive Battery Charger User Guide | Hybrid Automotive which, to my understanding of the voltages given here, would seem to suggest, in this case at least, it hopefully has enough charge left...I think... I am for now, proceeding on the theory...or mis guided hope if I am wrong... the control systems disconnected it in time to preserve some charge. Every blade reads 7.58, which I think is ok. If you or anyone else had more information about the charge level required to start, that would be welcomed, thank you.

 

Thank you Ed the Fox! I was presuming that 23% was enough to start the car. I am now understanding I am probably in error, though some have said it might be good for one or two start attempts. I was thinking perhaps that battery block 6 would be ok once it got started...or was in fact ok... I can not account for the fact that ALL the battery blades when tested w dvom read exactly the same 7.57 volts, INCLUDING block 6, with one exception, a blade that fluctuates on the meter an inconsequential amount..as I watch it...every time I check it, between 7.57 and 7.58. Can you account for why they ALL read the same. This battery is a rebuild, by myself. I took Gen 3 blades from a 70k wrecked gen 3, and replaced all the blades by taking the entire battery block set from the 3, and placing it in my prius. The battery I took out had 210k on it, but was still working after a previous rebuild I did replacing 2 bad blades. For the past three weeks I have been reconditioning it using 3 hobby chargers...up from one, when it was taking forever to charge to the hobby auto cut off as full (about 8.9 or 9) discharge to 4.8, recharge, etc. 3 times. I then discharge by 2800ma hour ...to set it at about 50% charge for storage...so I thought. I have found one weak blade to replace. Each blade after charge I can judge the health of by its discharge capacity. This varies from 6800ma hours to 6300 ma, mostly about 6550 ma hours on discharge after a full charge. If less than that I consider it a bad blade if reconditioning does not help it. I am about half done with this procedure. IT is very slow process. I note that after sitting for several months, ...pre my recondition efforts...the blades were all somewhat different in charge between about 7. 6 and 7.8. except for the blade that has proven bad, which was in the 6.7 range. Even after reconditioning the blades they all settle to various voltages over a few days to a week, which is why I find the fact that every blade in my prius under repair is 7.57 as per above it be odd. My plan had been, prior to your posts, to switch the battery packs after I got the car working, and had finished the recondition process I am doing on the old pack...(still two weeks or so to go)

I have some options for the battery. I could finish the recondition and place the old battery in the car....this will take me another 2 weeks to complete the recondition, OR place it in the car as is, to see if it makes a difference now, as the old pack is charged enough...but this would disrupt the effort to balance the packs all to the same charge after recondition is complete... I could start to charge the blades in the car, by say 2000 ma hours each, using all three charges...this will take about 3 days to complete if I stay on task...and will simply give the battery a boost charge. OR I could switch the battery on this car with my wifes gen 2 prius. .... and see what happens all around.

I think since I have some very good help from mr-guy-mann above, I am first going to at least try to see if basic power and ground are getting to my ECU, and trouble shoot that, as my first and next step. It seems to me that this is needed, no matter what...to get the com bus up. IF I can get it working, I will see if it starts...give it one chance. Then switch the battery packs at the risk of making us a no car family, and try that.

I remain open to and greatful for more advice...given this added context, from yourself and everyone. I really am just feeling my way along, as feedback and discovery and trouble shooting unfolds.

Oh to answer your question, or someones question, the car has 205k, and a battery from a 2011 gen 3 I installed about 5 months ago. Also let me clarify, I did not drive the car home on battery. The ice was working on the way home. ONLY odd thing on way home was blinking of all blocks in gas gauge. IT may or may not have been working when I started it a day later and drove it from the driveway into the garage, I did not notice, but that was when the red triangle first appeared. THEN I ran it down after I made repairs to the cat and started to take it for a test drive, w triangle still on, ...thinking it would go out when the car "saw" the new cat and O2 sensor. I got a block away and noticed no ICE start, tried to get back, then is when battery shut down, and shortly after the 12 volt died, weak from doors open during my repair time, died also, and I towed it back to the garage w 4 wheeler at about 7mph 1000 feet...and never again to have it be willing to even try to start either ICE or go into drive or reverse, even after a full 12 volt charge. ...BUT the gas gauge...all bars, were flashing, both on the way from the shop I got the estimate at...20 miles from theft site, and on the 2 mile drive back to the driveway...SO I now suspect, but do not know (does anyone know what that means) the ECU bus was down, from the shop to my driveway, driveway to garage, and on the ill fated battery draining "test drive" that followed my repair of the cat and O2.

 

Thank you! I am realizing the battery may be too discharged, and my thinking it was charged enough, error in thinking. (See my other reply to ed the fox 5 above.) I think I will try somewhat to see what is up with the com bus, maybe let it try one start, and if that does not work, change the battery with one I have in another 2nd gen prius...IF I can get the com bus working. Low drive battery with good 12 volt would not give me no ECU com communication...I am assuming this to be true anyway. SO this com problem is my next first priority I think.

 

I finally completed getting these readings done, as per your instructions above. I FOUND a problem! But now I do not know how to pin down the problem source and fix it. I am not adept with these wired schematics, to see what to check next. I am hoping for help. SO all readings were as specified except for ECU connector E7 pin 4, which you said should be about 12 volts at all times. IT IS zero volts at all times, key in ready or key off. SO this is a problem, no power getting to ECU connector 7 pin 4. Could you or anyone who can read these schematics well, tell me were to pursue looking for the break in the line....how to fix this? I am hopeful...now as we have a definite reason I think for com bus to ECU to be down, and ECU offline. Waiting to hear back??.... thank you...