2001 Prius Technical Info

Is the question, How much ripple current can the battery tolerate? Are you talking about ripple from the inverter, or ripple from a home-built charger? I think the answer is quite a bit more than 4 VAC, given what I have seen with a PHEV DC converter on a Gen II.

 

I don't have any experience yet observing hv ripple on any prius models.I would however with my 40 years electronics / electrical experience say that 4 volts ac ripple would be acceptable.. Unless your hv battery is showing signs of weakness, or not holding charge or not taking a charge.. This 4 volts of ac ripple could indicate high resistance in one or more cells. And if your on the orignal hv battery this would be the reason for high ripple..but I cannot tell you what the normal ripple while the car is charging the hv battery please give more details what is not working .. Is the car driveable?

 

Mwilson. I've just read everything and am refreshed with the problems on this car..You have done some excellant testing and trouble shooting..You report 265 volts under heavy reverse load-----this is excellant...plenty of power from hv battery all the way to the motor/gen # 2.... code p3030 obviously erronius (bogus, not real)...something is wrong with hv ecu....sense wires?...software/firmware version on ecu not compatable or different versions on hv ecu's/firmware for 2001 prius's ???????You stated also the monitored hv voltage goes to zero volts when the codes are generated.......the only way for the voltageto go to zero volts would be if the main hv relay is being deenergized (by ecu) upon codes p3030 and p3001 being generated....this is not likely... the hv-ecu is reporting falsely zero volts and open or high resistance battery buse...either sense wires are mis-connected, missing, or incompatable message being hv ecu... if your certain sense wires are connected properly... it would seem there must have been some kind of revision ecu boards with different software sending different battery status messages to main system computer...The ecu is obviously receiving commands to energize prechargerelay and main hv relays other wise car would not start or drive in reverse.... oh maybe ecu not transmitting...but multipullhv ecu have been in this car I think?? my guess soft/ware on hv ecu. or different ecu's with slightly different software/firmware (used in 2001 prius) a good question for toyota...and toyota should be informed how much work this software revision has caused an otherwise happy prius owner..If I was a concerned ceo of toyota I would give you a brand newprius for your efforts and your obvious love for the 2001 prius...... plus and appology for the dealer not aware of ecu revisions..Be vary carful disconnecting mg1 and going to ready mode.. I would not do this without looking very closely at the inverteroutput transistors circuitry to see if they can be powered with no-load (mg1 load) this could blow the transistors...In this mode mg1 disconnected the ice cannot start up... but the transistors will try to spin mg1 and fail to do so... reportingother error codes (i would think)...very interesting case... Cant wait to hear more I will stay close to prius chat this time.... sorry for not reading all this after my may posting..

 

Hello again mwilson.. I have a follow up thought on your 2001 prius..There was a very sharp indivual here on prius chat that posted all abouthis own plug in prius hybrid conversion....He used lithium iron batteries, built his own pack, charger/maintainer/ballancer and hv bat ecu!!!!!As I recall his hv battery ecu design was a listen only device (it didn't send any messages) So I question now if the hv battery ecu monitors hv battery voltage/current or is the battery monitored by the inverter ecu?????The hv battery monitor function has to be handled by one or the other (hv or inverter) ecu's .... if this function is done by the inverter ecu Iwould probably suspect software/firmware in the inverter ecu...I will have to look back at the history and orignal problem with this car.. I posted for a couple of different prius's with similar problems....and also where hv battery is monitored (inverter or hv bat ecu)...The hv bat ecu also sends battery temp and multipul cell voltages...Im just not sure how that guy built his own hv battery ecu without sending capability.... there fore the error codes could be generated inthe inverter ecu...if that' where the battery monitor fuction is handled??What did you use that reported zero volts on the hv battery???????Do you know if any software could have been updated by the dealer..talk later..

 

Hello again MWilson... I have more thought on your prius problem.You had ask about acceptable level of ac on hv dc battery.. stating you see 4 volts ac and suspect even more..I can hear through my gen II prius stereo while in aux mp3 mode with mp3 player off that the prius has a significant amount of ac noise while in regenerative braking mode... the more braking the more alternator like ac noise is heard through my prius stereo..... this suggents that theac noise from mg1 is traveling to battery pack and accrossed dc to dc converter and getting through to 12 systems...stereo, ecu's and probably everything...Here is what you should do....... Add an additional engine block ground to the car body with at least 14 gauge wire.... and an additional ground at 12 battery neg. terminal to new body ground location...I believe you have significant noise on computer can buss that communicates with bat ecu.. also if the small wires (can buss wires) comming from hv battery are bundled or cable tied to high voltage wires....try to unbundle and seperate smaller can buss wires from hv large wires.... for extra noise isolation... if this doesn't do the trick for you start checking can buss shielding....Digrams for gen II show can buss to be shielded with grounded shielding.... overall try to eliminate electrical noise from ecu's, 12 battery supply,and 12v ground...

 

Final analysis for mwilson.... CAN buss being loaded down by a certain ecu, gen II diagram shows gateway, skid control, steering control, steering sensor, battery, engine,and dlc3 ecu's all connected in parellel at junction 15 to CAN buss....each will have to be isolated while observing canl & canH signals with oscillascope to see which ecu is loading down theCAN BUSS... or you might just jump to the more likely dlc3 ecu (diagnostic/smog/code reader port ecu) witch probably gets glitched/zapped the most by careless technicians/smog testers.... Should be easy to disconnect dlc3 ecu from Can buss at junction 15.... but better reference gen I manual which could be a different juncion block than gen II....Because battery ecu resides at the most distance location from dash board it will be the first device (ecu) to experiencecommunications loss on loaded-down compomised can buss... I believe battery status messages battery ecu are notbeing received at the hv ecu (hybrid vechicle ecu)....thus system generates error messages.... Noise on can buss could also be a factor in the loss of communication from bat ecu on can buss, when mg1 is generating noise (mg1 noise is normal)..the noise covering up the data from weaker distant bat ecu..... In my previous post I use hv to indicate high voltage and I call the battery ecu a hv battery ecu (high voltage bat ecu)... this could be easily confusing with hv ecu (hybrid vechicle ecu) which is the heart of the whole system.. sorry for any confusion..Look for loaded or noisy Can buss to be the cause of mwilson's gremlins..One more source of noise could be a shorted cell in 12volt battery causing additional dc to dc converter noise due to more chargecurrent at the bad 12 volt battery....