mux
Posts: 297
Joined: Sat Jan 13, 2018 3:52 am
Delivery Date: 13 Oct 2011
Leaf Number: 6177

Re: Leaf 2012 won't start or charge [SOLVED]

Wed Feb 27, 2019 4:37 am

That is basically everything in the HV JB. So it works. I'd be surprised if replacing it will make any difference.

mauiEVenthusiast
Posts: 18
Joined: Thu Aug 16, 2018 6:06 pm
Delivery Date: 17 Aug 2018

Re: Leaf 2012 won't start or charge [SOLVED]

Sat Mar 02, 2019 12:42 am

mux wrote:That is basically everything in the HV JB. So it works. I'd be surprised if replacing it will make any difference.
I tested everything in the Battery Junction Box. What the manual calls the High Voltage Junction box is the large metal case behing the inverter on a '11, & '12 basically up against the fire wall. It is between the battery case, and the inverter. It has HV contactors that connect the battery to the charger inputs, and outputs that go to the AC compressor, etc. Hope replacing it is the solution to getting this car running. It is a pain in AR$E to get to though, at least on the '11 & '12. the '13-'17 leaf has it right on top of the inverter, easy access....

mux
Posts: 297
Joined: Sat Jan 13, 2018 3:52 am
Delivery Date: 13 Oct 2011
Leaf Number: 6177

Re: Leaf 2012 won't start or charge [SOLVED]

Sat Mar 02, 2019 10:16 am

Oh... ouch. My condolences, that is just the worst place to have to work on the Leaf. Not easy to get into from either above or below.

mauiEVenthusiast
Posts: 18
Joined: Thu Aug 16, 2018 6:06 pm
Delivery Date: 17 Aug 2018

Re: Leaf 2012 won't start or charge [SOLVED]

Wed Mar 13, 2019 11:44 pm

You got that right. It was pretty miserable. Finally got the cradle out, & the junction box too. I changed it, put everything back, connected the 12V and got exactly the same codes... Going through the DC to DC junction box (as the service manual calls it) which I had been calling the High Voltage Junction Box, I see that I was supposed to verify it had less than 0.1 Ohms resistance between the aluminum housing & the vehicle chassis. Going to test the resistance tomorrow.

I am pretty much stumped at the moment. Guess maybe I could try another inverter. the inverter condenser code p3176 is still present, though supposedly the p311C code changing the junction boxes was supposed to alleviate was higher priority..... Will get to the bottom of this eventually...

mauiEVenthusiast
Posts: 18
Joined: Thu Aug 16, 2018 6:06 pm
Delivery Date: 17 Aug 2018

Re: Leaf 2012 won't start or charge [SOLVED]

Mon Mar 18, 2019 2:28 am

I decided to pull apart the recently removed DC to DC Junction Box. After some poking around, I discovered a blown fuse. I am not sure if it is an AC compressor connector, the Brake system Power supply, but I will investigate that tomorrow. Perhaps with the blown fuse, the car VCM detects a fault & does not want to go to allow the car to power up or charge. I am not sure.

mauiEVenthusiast
Posts: 18
Joined: Thu Aug 16, 2018 6:06 pm
Delivery Date: 17 Aug 2018

Re: Leaf 2012 won't start or charge [SOLVED]

Thu Mar 21, 2019 12:51 am

OK so the blown fuse appears to be to the PTC heater. Not sure if that would cause the vehicle to not start, & set the P311C code. Seems to me I've seen several threads about Leaf's run with no heat, and frankly we almost never need heat here on Maui. I pulled the used DC to DC Converter back out and opened it to see what was going on with it. The fuses were all good, but the inside of the box smelled kind of like burnt electronics. I think the DC to DC stepdown converter may have blown when the part was in a vehicle in an accident. The 12V output stud was badly bent from the accident, so it is likely that the positive was shorted when the battery was crushed, etc.... I didn't get a good look at the crashed car before the parts arrived, but I see some damage to the case & the blank plug above the 12V output stud. I swapped the blown fuse into the cars original DC to DC Junction box. I tested the Quick Charge Relays, and I am not sure what else I can test here with a multimeter and a 12V power probe without putting the unit back into the car. I am considering leaving the PTC Heater disconnected and defeating the connector interlock, at least that way I don't blow the fuse again before I test if the car will power on.... I may need to replace the PTC heater, but I'll need to order a MEGGER t test it properly I think... The blown fuse is probably an indication it is failed, unless the Dealer tech blew the fuse when they were trying to diagnose the car. I found the boot on the HV cable at PTC Heater all loose and pulled back.... Hmmm

mux
Posts: 297
Joined: Sat Jan 13, 2018 3:52 am
Delivery Date: 13 Oct 2011
Leaf Number: 6177

Re: Leaf 2012 won't start or charge [SOLVED]

Thu Mar 21, 2019 3:59 am

That boot easily gets loose, in fact, on our 2014 test Leaf it's loose as well, you can just pull it back and expose the shield.

The PTC heater, if it fails, shouldn't cause the car never to go into ready mode, it's a removable error.

The 12V DC/DC however may be a culprit, if it doesn't work or if it is disconnected the car will always refuse to start.

I'm not sure either what your issue may be at this point, its all trial and error at this point.

mauiEVenthusiast
Posts: 18
Joined: Thu Aug 16, 2018 6:06 pm
Delivery Date: 17 Aug 2018

Re: Leaf 2012 won't start or charge [SOLVED]

Sat Mar 23, 2019 12:11 am

@mux

Thank you so much for your help. Got busy with a bunch of Prius that came in. Will have to wait to get back to the Leaf. Mahalo, & Aloha

lock174k
Posts: 4
Joined: Thu Feb 14, 2019 7:13 pm
Delivery Date: 15 Feb 2019

Re: Leaf 2012 won't start or charge [SOLVED]

Tue Mar 26, 2019 11:07 am

hi maui , any updates,please ,got a leaf with fault codes p31e0 and p31e2 thanks paul

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