Reversed polarity... Now what?

Ok,

Step one, use your Prius-aware scanner and see if you can communicate with each ECU. See what codes and status show. Strange as it may seem, the built-in, 'diag' screen may help identify what units are responding. I'm not an expert in this area but it is a good place to start. Someone else may have something handy.

When you turn the car ON, what is the 12V voltage? There is a 125A, fusible link that is supposed to protect the 12V DC-to-DC inverter. If you see 13.8V or there about, you are lucky. But I've seen a blown, 12V converter (have one handy in fact) and blowing it up is pretty ugly (parts inside ugly with burnt leads.) Inverter replacement is the only known cure.

Bob Wilson

 

Your code 3030 indicates its one of your batteyr voltage sensing wires broken. What that means is remove the battery cover and look on the front side where all your sensing wires are attatched to the battery terminals. One of them will be broken . You have to look very close because they sometimes break in the orange case right next to the terminal itself. And yes the car will not start if one of these is broken.. PS your other codes i would not worry about at this point, they are most likely related to your car not starting.

 

You're right:

• 120A at battery
• 100A at inverter

Bob Wilson

 

Ramu,
So the dtc's you have now are p3030, c1215, c1241 and c1259? The car should at least attempt to start with those codes, does it?

 

Does any Prius generation even have a starter? I don't think so.

 

I would recommend getting a 'repair' scanner because it will show more metrics than a traditional scanner:

• miniVCI - uses Windows XP although some report getting it work on more modern versions.
• AutoEnginuity - a little more expensive, it has TechStream capabilities. Be sure and get the Toyota option.
• TechStream Lite - the gold standard, some sort of 'rental' licensing, I don't have any experience with it.

These scanners will show more details including the subcodes of the inverter. But I'd like you try one quick test:

1. Try to start
2. Turn back to IGN
3. Try to start again

There is an obscure signal that goes from the inverter back to the traction battery, safety interlock switch, and then to the HV ECU. When I say obscure, I'm not whistling Dixie as I've not been able to tell if it is AC or DC. Regardless, if it is broken or failed, the car will not initially start. But the second attempt after returning to IGN works.

Bob Wilson

 

Is your battery interlock fully seated? This is for a Gen II. I don't have a pic for the Gen I but it should be similiar (see page 21-118).

 

HHHHMMM,not sure where to tell you to look,but that code 3030 will prevent the car from starting. The only thing that i know will cause that is the sensing wires however you stated that you replaced them. I would check the harness plug where it gets plugged in to the ECU. Also you can take a multi meter and check for continuity between each wire at the plug and the other end of the wire where it hooks to the battery.. That is how I found mine..

 

Great news so far!

It's possible your brake computer latched a trouble code while it knew there was a problem logged by the battery or hybrid-vehicle computer. (They have to keep track of each other's status to make regenerative braking work.) Or its possible the brake computer has some other issue.

If your Prius-aware scanner hasn't been delivered yet, the brake computer is one of the computers with an alternate way you can read the trouble codes, by counting light blinks ... you could search the forum for TC CG blink.

-Chap