Idling & Running Voltage Question

Running or idle car on I think needs be 13.5 6 7 or so . It sounds like the charge circuit is somewhat low . Maybe battery ECU or such . Need a deep scan with toyodas tech stream software. Will pull codes others cannot see

 

12.1V is low for a static or "just sitting there" reading on the battery. Normally a fully charged battery should be 12.6 to 12.8V. So this one could be "just" undercharged from infrequent use or it could be deteriorated and have low capacity.

You could get the battery charged then load tested, or just plan on replacing it anyway- then it would be one less thing to worry about. Either way the 12V battery is a minor normal maintenance item.

The 12.1V "reading" while running has me skeptical, as the car cannot operate very long unless the inverter - DC converter assembly is working correctly. Normally in "ready" mode it produces about 14.0V to run the electronics and low voltage stuff- and charge the 12V. If it doesn't work then the 12V would discharge rapidly, some warning lights would come on the dash, and the car would "die" and nothing much would operate. So I don't think that they got that measurement correct or the car wasn't in "ready" mode.

Did this inspection service scan all 14+ ecu's in the car for any trouble codes?

Also, there are a few known concerns with older Gen2 Prius like your 2008h one of those being the condition (and eventual need for replacement) of the High Voltage battery.


Posted via the PriusChat mobile app.

 

A happy G2 12 volt battery should live at 12.6. Your saying they see 12.1 volts with car off and also when car is Ready?

Highly doubt that if so the Inverter dc to dc is blown which would instantly throw the red triangle of death on the dash.

Why do you want a G2 so bad? There a nightmare to own now with the cat thefts and I think New Jersey is a carb state so if they swiped your newly bought g2 you would be up shits creek as the Toyota cats have been on back order for months and are $2000.
Not to mention it needing a new hybrid battery is almost a guarantee.

Plus there all beat to death it’s a 15 year old car.

 

Finally secured had a company go out and do a PDI and check the car on and on and on My god this sounds like you're qualifying for a bank loan for a new home it's not buying a 20-year-old used car holy Christ That's just great reading..

 

In another country I guess ? Seems like an awful lot to put oneself and companies through for what would seemingly be a I don't know regular purchase or something I mean if I enacted all this every time I bought something I would be spending so much money to the pre buying companies or whatever they called. Fees

 

What that means is the ppi company does not know what they are doing. Its almost impossible that three gen2s would all have low 12v bus voltage when "idling". Odds are good they measured it in the shutdown state and it read 12.1v and then measured in the On state (which is not Ready/idling) and it also read 12.1v. Only in the drivable Ready state does the Inverter provide the 13.5-14.5v charging voltage.

Given this is rudimentary hybrid system knowledge, I would not trust anything they reported. They probably don't realize it takes an advanced hybid enabled scanner to see all the codes that are not on the OBD2 bus.

Another reality is a hybrid battery is difficult to evaluate until it has failed. Apps like Dr Prius try through a convoluted process of forced charging and accelerated discharging while driving the car. Its better if an older hybrid has had a new battery installed in the last two or three years and it is documented. New means new, not rebuilt, reconditioned or repainted.

 

My daughter's same way . Pays companies to do for . Spends alot of time complaining about it too . And they're no recourse of course. Similar to housing inspection racket. But do get that piece of mind . These buis. Are the Candace n Ben's of the auto industry I guess . My opinion . NFC vehicles is a comin...

SM-A715F ?

 

First thing I thought when I saw the numbers was that those people must not know what they're doing.

 

Just curious, how much are they asking for the car and how many miles?

 

OR.....maybe YOU could enlighten US on the right way to use a public forum like this without getting your feathers all ruffled.

Note: this forum software will quote the post you are replying to FOR you. You know that, right ??

 

I agree with the others that it is extremely likely that the person who did the check just doesn't know how to check the battery voltage of a Prius properly.

12.1 Volts is acceptable when when in "ignition on" mode, with ECUs, displays, water pump, fan, etc. drawing a moderate current from the 12V battery.

I would suggest having a "Health Check" done, using the Toyota "Techstream" diagnostic system at a Toyota workshop.

 

I don't put much faith in a general statement of "no codes came back". Many scantools cannot talk to all the ecu's on a Prius, so there might be codes but you wouldn't know.

I much prefer a report generated by the scantool that lists all the systems on the car that were interrogated and that each one did not have any codes. That's 14-16 different systems on a Gen2 Prius. I would test drive the car-hard accel and braking, do several ABS stops - then re check everything for codes.

I also like to see that all of the OBD2 monitors in the engine computer (ECM) had completed and no problems reported (ie, no codes or pending codes).

Posted via the PriusChat mobile app.

 

It appears that YOU need to take a long hard look in the mirror......and work on not jumping to conclusions quite so quickly.
The evidence that you provided in this thread really makes it look like you didn't learn the lesson very well.
AND......that statement is intended to be helpful. But you likely won't take it that way.

 

I assumed you were in another country because some of your posts sounded funny kind of like mine and I'm a foreigner no matter and I don't care how you buy your cars but paying folks fees just seems to me kind of like passing the buck. But that's just my personal opinion I don't know anything off base or off color about it doesn't really make any difference where you're from or what you're doing you buy a car anyway you want to buying a car I would certainly want to know personally how to check basic voltage and some things it's just a personal thing