Rebuilt 2006 Prius Battery

Hi brian, have you checked that the battery voltage is still ok at those terminal after the short. If there was any fuse or link that had blown it would have to be before the arc point, so you'd lose the voltage at those terminals. Also it would be worth checking the voltage just to make sure no cells had obvious damage from the short.

If there's no fuse or link gone, and the voltage is ok, then there's the more unfortunate possibility that a voltage surge may have fried something. Short circuits of course cause the voltage to dip (possibly to zero) rather than rise *but* the currents are massive, and that means that as the short is cleared there can be a massive transient voltage surge (inductive kick). That would be my biggest worry in this scenario.

 

Yes should have 200+ DC volts across the 2 orange leads going into the contactors. One is pos the other neg as in the picture. If not the safety switch is blown recheck that fuse.

If you do have 200 volts DC either the battery ecu or the hybrid vehicle control ecu is blown. I would go for the battery ecu first. Its the little box in the trunk on passenger side next to system main relay. The hybrid ecu is behind glove box to the right next to body standing up on its side. Its sandwiched together with the engine control module.
2 boxes together.. The hvc is on the body side.

Just for giggles since you have a volt meter out check that there's 12 volts on the front jump points under the hood first.

 

There's no voltage on the other side of the contactor because the contactor is not engaged. Its a relay thats not being closed because the coil control voltage comes from the vhc.

Not busting your balls here just talking man to man. The fact that you don't understand basic relay operation tells me your not an expert here on this basic stuff so be really careful around this open battery box. That battery will really hurt you.
Just the flash alone can blind you permanently. Is it worth it? Take it to a Prius battery expert.

Whats the exact DC voltage on the 2 orange leads coming into the contactor?
The 3 contactors relay coils are controlled by 3 wires. One wire each coil. a yellow,green and red. These come from the vhc. There will be no 12 volt RELAY COIL ON voltage on these wires if the vhc detects an anomaly report from the battery ecu.

Normal scenario you push the start button the 3 relays are energized by the 3 control 12's the relay's close and present 200+ dc volts to the Inverter.

If you have 200+ DC volts on the 2 oranges coming in you have a blown ecu.

 

If your really really lucky you didn't damage the Inverter.

 

What is a precharger?

 

Yeah they put the big battery load across 3 relays with spark quench resistor so the contact's in the relays don't
see massive inrush and the contacts themselves don't get burned. Its as assembly.

212 is good probably battery is ok. Easy way to test relay see if you can monitor one of the small yellow,red,green relay coil wires. With dc meter on one of them have someone push the start button. No 12 volts there upon startup
the vhc is not happy. If there is quick 12 volts then goes away without a relay click the relay may be blown but they would all have to have blown control coils. This is unlikely. I can almost garantee no 12 volts there ever now.

My money on blown battery ecu. This can be confirmed by pulling DTC codes. If you end up towing this to the dealer make sure first thing they do is pull all the codes and get the printout and post back here. The codes will confirm which ecu is unhappy. There will be alot of codes lol.

But bad news is so many things going on there in that battery circuit. The gateway may be blown too.

Btw, is the method of putting the cover on not supposed to be done with the battery in the car?
I would have put a piece of canvas over the contact area....put the cover on...then pulled the canvas out and bolt it up or something along those lines. Your really lucky the battery didn't explode on you or shock the shit out of you.

Your not giving that battery enough respect!!!!! LOL!! Don't make it teach you that!!!

 

It would be an "inrush" contactor Ed.

I don't know the specifics of the Prius, as fortunately I haven't had any HV problems with mine yet. But it's fairly common in inverters with large capacitors to have an inrush contactor. This is basically just a second contactor, in parallel with the main one, that has a series resistance to limit inrush current. Typically the controller would energize the inrush contactor (while keeping the power demand of the inverter set to zero) for a second or so before the main contactor is energized. This allows the capacitors to charge through the series resistor to avoid a huge current spike. After a second or so the main is energized, which effectively bridges out the series resistor and allows full power to be supplied to the inverter.

 

Got it...thought I covered that:

"Yeah they put the big battery load across 3 relays with spark quench resistor so the contact's in the relays don't
see massive inrush and the contacts themselves don't get burned. Its as assembly."

​

 

Haven't heard the term precharger in a while and did not compute. It limits the inrush to the inverter also.
I see a resistor in series with the contact on relay #1. Thank you.

 

There are no arc quench components associated with the Prius battery contactors. There is a precharge resistor that limits inrush current into the invertor. Toyota calls this the System Main Relay. See Prius PHEV TechInfo - EAA-PHEV.

You'll notice from the timing diagram that the Prius does two short circuit tests before engaging both main relays. I imagine if it finds a short it throws some codes that you would have to clear before operating the Prius again. These will be proprietary codes specific to the Prius. You will need a scan tool which reeds these codes.

 

Doesn't anyone read posts before they reply? Uart went over this quite clearly.

 

LOL I typed that before reading your reply #10.

 

Interesting. Good work. I dont see any individual nags about the battery itself so thats good.

I assumed the battery ecu would be the first to go as its so closely attached to the battery itself upstream of the short. Since you shorted the hot side on unclosed relays I bet nothing after the relays got spanked.

But maybe just the relay got blown up and not the ecu.

The negative relay is the relay the yellow wire #3 goes to. See if the orange cable from the battery to that relay where its bolted to the relay is burned up where the short happened. Maybe it was a such a bad high energy short it blew out the coil side of that relay.Rare but never know. Or that bolt/connector is burned up and not making connection to the relay. Thats the hot side be careful there.

To check its coil If you can unplug the small conductor plug measure the plug where the yellow-green-red small wires enter the relays. I think you can see the terminals there attached to. Those are the 12 volts coil power from the hvc ecu to each relay coil. Put one side of ohmeter on each of those in the plug. They should show a short to ground through each relay coil. Maybe the yellow is open to ground. Open coil on negative relay.

The only other way to see if the relays will work is remove the orange relay output wires to the Inverter and disconnect the small wires plug and insert 12 volts to each coil terminal and see if the relays click closed specifically that negative relay yellow. Make sure its not connected to the hvc as you don't want to back feed 12 to the hvc ecu.