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Tim Mohr
Tim Mohr, ASE MASTER TECH
Category: Toyota
Satisfied Customers: 15121
Experience:  30 YRS EXPERIANCE, AUTO AND TRUCK,FOREIGN AND DOMESTIC, GAS AND DEISEL
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Red triangle , changed battery 12v 12 hrs later came back on

Customer Question

Red triangle , changed battery 12v 12 hrs later came back on in display car with askerisk . ideas
JA: Have you tested the battery? Is the battery fluid low?
Customer: Battery is brand new optima
JA: What year is your V?
Customer: 2007 prius
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: Yes , changed 12 v battery
JA: Anything else you think the mechanic should know?
Customer: With car on but not ready shows 11.8 v. Checked codes no codes
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Toyota Mechanic about your situation and then connect you two.
Submitted: 5 months ago.
Category: Toyota
Expert:  Tim Mohr replied 5 months ago.

Hi, my name is ***** ***** is usually caused by a bad alternator, do you have a volt meter? I can help you verify this?

Customer: replied 5 months ago.
This is a hybrid
Customer: replied 5 months ago.
Does prius have alternator
Expert:  Tim Mohr replied 5 months ago.

Yes, for the 12 volt system, but lets be clear, is it the large red triangle that is lit?

Customer: replied 5 months ago.
Customer: replied 5 months ago.
Lg red triangle with asterisk
Expert:  Tim Mohr replied 5 months ago.

Ok, do you have a volt meter? we need to see the batery voltage when off and when running?

Customer: replied 5 months ago.
Ok
Expert:  Tim Mohr replied 5 months ago.

let me know,Tim

Customer: replied 5 months ago.
Where do you want me to check voltage
Expert:  Tim Mohr replied 5 months ago.

at the 12v battery

Customer: replied 5 months ago.
ok
Customer: replied 5 months ago.
12.5 when off 12.3 when on
Expert:  Tim Mohr replied 5 months ago.

and the trinagle is on right now, when running?

Customer: replied 5 months ago.
That was checked at battery in trunk
Customer: replied 5 months ago.
car will go to accessories but when hit on button twice dash goes dark
Expert:  Tim Mohr replied 5 months ago.

ok, it sounds like the inverter/converter is going out, have you pulled the codes from the computer yet?

Customer: replied 5 months ago.
Push start button once dash lights on hit twice goes dark
Customer: replied 5 months ago.
I did yesturday no code did not pull after putting battery in. I can go do that again
Expert:  Tim Mohr replied 5 months ago.

If the tringle is on, it will have a code,Tim

Customer: replied 5 months ago.
Check with obd?
Customer: replied 5 months ago.
Or system check in dash
Customer: replied 5 months ago.
Im going to pull codes again
Expert:  Tim Mohr replied 5 months ago.

Yes, will need an OBDII code reader or scanner,Tim

Customer: replied 5 months ago.
Tim codesc1259 hv system regenerative malfunction
C1310 malfunction hv system
Expert:  Tim Mohr replied 5 months ago.

give me a second to look up these codes,Tim

Expert:  Tim Mohr replied 5 months ago.

Ok, these code indicate problems with th regeneration system of the high voltage system, do you have a scanner

Customer: replied 5 months ago.
volt meter and obd checker.
Expert:  Tim Mohr replied 5 months ago.

those wont work for diagnosing this, this is a High Voltage system, and can be dangerous to start probing around,Tim

Customer: replied 5 months ago.
What caused these codes BEST GUESS
Expert:  Tim Mohr replied 5 months ago.

the most common problem is the brake regeneration module is bad, but it will need to be verified to be sure,Tim

Customer: replied 5 months ago.
If I reset the codes ( clear ) may it start
Expert:  Tim Mohr replied 5 months ago.

It might, but it will return,Tim

Customer: replied 5 months ago.
Ok thanks
Expert:  Tim Mohr replied 5 months ago.

Anytime my friend, please dont forget to rate me so I can get credit for helping,Thanks,Tim