2013 Prius c will try to start the gas engine but stop and not go into ready mode.Hybrid batteryLow

Are you sure your 12 Volt battery is OK? That is what boots up the computers into READY mode and closes the Hybrid battery switch.
If the 12 volt battery is low you can get all sorts of strange, false errors.

 

you need a grid charger (@jeff652) to charge the hybrid battery, or have a dealer do it.

 

It is certainly possible for both batteries to be low after 8 months, and the 12 volt is easy to charge, so I would definitely do that, just for peace of mind.

That said, could you describe the behavior as clearly as you can? Your subject line says the car will "not go into ready mode" and your post text says it will "not stay in ready mode will only for a second". Which is it? Does the car light the READY light briefly, then give up after an attempt to crank the engine?

You haven't mentioned the source of your information that the traction battery is low. Does that come from the battery bar graph on the MFD, or some other instrument?

In any case, after 8 months, you are probably right, and it gets lower and lower with every attempt to start the engine, and it is difficult to charge (special equipment required), so one thing you do not want to do is keep trying over and over.

In the worst case, you may in fact need to charge the traction battery before the car will start. That may require an appointment at a dealer, though there might be other options depending on your skills and willingness to tangle with lethally high voltage DC.

If you have a chance to read any trouble codes from the car, I would do that and post them. They are unlikely to be false. The idea that a low 12 volt produces false codes is all over PriusChat, but never (that I have seen) with the four ingredients that would be necessary for an actual example, namely:

• Car was scanned for codes
• Codes were looked up in Repair Manual to see what they meant
• Troubleshooting procedure was followed to check car for the indicated condition(s)
• The indicated conditions were shown not to exist

If it is so common for low 12 V to produce false codes, it should be easy to produce such an example and post it on PriusChat, but I've been around here since 2008 and not seen such a posting. I've seen a lot, though, that just throw out "could be false codes because of the 12 V" in advance of anyone checking the possibility that the codes mean what they mean.

-Chap

 

Sorry but BAD advice.
He needs to check the 12 V aux. battery first.......or have a dealer do it.

 

Parked for 8 months? Any steps taken to mothball it, negative battery lead disconnected for example? Or that's all she wrote? If so, almost certainly the 12 volt is dead, and likely not recoverable. Check that first, get it resolved, then go from there.

Was this outdoors, in a garage? How many miles on it?

 

thank you, try reading the o/p again, i can only go by the information provided.

 

He is making an assumption......and you are following right along.

 

is he, or are you?

 

I think we all are...

 

without the o/p, we're groping in the dark.

 

On our regular 2010 Prius I've never seen less than 2 bars. Get codes read?

 

The problem with this report is: You don't know without taking a voltage measurement AFTER the charging and startup attempt whether or not the 12 V battery is actually storing the charge you gave it and is able to give it back.

I suppose that a REALLY dead hybrid battery could be a problem but......one bar is not "dead" and if it was dead, how did it GET that way.

The odds still favor a problem with the 12 V battery; more testing is needed.

 

I have a standard procedure for this kind of situation.

Especially helpful when you don't have any diagnostic tools.

1) get 12v up to healthy range. Double check that post and ground connections are secure.
2) remove air cleaner box so you can remove MAF and clean MAF with MAF cleaner
3) unbolt throttle body and sop up and oil from inside/top of intake
4) with car off, spray some starter fluid down the throttle body's butterfly.
5) quickly hop in car and put in Ready mode. The car will try to start gas engine.
6) quickly hop back out and judiciously spray additional bursts of starter fluid on top of the butterfly to keep car running.
If car starts to run properly, stop adding starter fluid.
7) replace air cleaner box

I just did this with a car that someone had killed the 12v.

If you really did get the hv battery too low, then you will need to use a high voltage charger to charge up the pack first.

You won't know the hv battery voltage without diagnostic scanner, or without opening up the pack.

There are some other more risky/life threatening ways to "jump start" a hv battery if you have a spare Prius. But I would only employ them in an emergency and when I had high voltage safety protection equipment.

 

So what is your plan to charge the battery?
I suspect a Prolong grid charger would work. I would call Hybrid Automotive to verify first though.

Officially the dealer needs to get in a special charger to charge the traction battery.

 

it wasn't the 12v? shocking!