Leaf 2012 won't start or charge [SOLVED]

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I don't have any experience with that, but I'd imagine it is. If you can try to swap it for little cost, you can certainly try.
 
The large antifreeze reservoir at the drivers side front was almost empty. The other smaller reservoir containers were not empty. After I filled it with the correct blue antifreeze and reset the codes, I only have the following codes now.

C118C 0109 ABS EV/HEV System BRC-126
C1A6E 0109 Brake EV/HEV System BR-146
C1A70 0109 Brake Brake Control System BR-160

Which one do I tackle first?
 
Those trigger everytime you remove 12V power or if other critical codes occur. You can just clear them all in random order.
 
I have been posting in another thread that I found about the car we got ( https://www.mynissanleaf.com/viewtopic.php?f=30&t=26343 ), but it seems like this thread may be more on point.

My friend who has several 2013+ Leafs bought this Leaf here on Maui.
The battery was replaced by Nissan in 2016. It shows a SOC of 67% and a SOH of 92.18%.
I got those numbers with Leaf Spy Pro. There is no battery charge level or range displayed on the GOM...
Car will not charge, or go to "ready" mode, and go into Drive or Reverse.

There are a lot of trouble codes. I think these are the most important ones here.

P0AA0 00C4 EV/HEV QNRH Hybrid Batt. Positive Contactor EVC-141
P317A 00C0 EV/HEV Motor System EVC-247.
P0A1B 000A MOTOR CONTROL Drive Motor A Cntrl Mod TMS-46
P0C79 000A MOTOR CONTROL Drive Motor A Inverter Voltage TMS-70
P324F 000A MOTOR CONTROL Drive Motor A IGBT TMS-99

The rest of the codes are ABS, HVAC, or Multi AV codes which I think are a result of no HV to the HV Junction Block.
Now this is my first time I have worked on a Leaf, however I have been servicing the family Prius for 13 years. I have fixed a lot of other Prius, and changed everything at least once. Inverters, traction batteries, HV Contactors, Drivetrains, ABS modules, etc. I have an associates degree in electronics, so at least I know enough to not complete a High Voltage circuit with myself...

The original owner was driving normally one day, and suddenly a bunch of warning lights lit up, and the car lost all power. The owner had the car towed to the dealership. They pulled all the same codes I got on the invoice. The dealer paperwork says the inverted is at fault, & the motor has a slight fluid leak so they want to replace it too. The repair quote was over $12k in parts, & over $2k in labor. Also the dealer replaced the 12V battery as part of the diagnostics protocol.

I have the factory service manual now too. According to the manual so far I have found the inverter problem code and the HV contactor code receive the same Priority level in the troubleshooting flow, but the code P0AA0 HV contactor diagnosis page says if there are other DTC's present, deal with them first, as the P0AA0 may be caused by the other problems... That is good I suppose since it appears the HV contactors are inside the battery case, & I do not want to drop the battery and split the case if that is not needed... Still it seems to me that none of the HV componenets will work if the +HV contactor has failed, and the contactor/precharge assembly is the least expensive component of the suspected failure points...

Any pointers will be greatly appreciated.

Mahalo
 
So I have replaced the inverter with a used unit, & found the HV contactors were both welded shut. I replaced the contactor assembly, tested the new contactors, measured the precharge resistor, (30.9 ohms) and tested the precharge relay. With the battery pack back in the car I still cannot get the vehicle to charge. When plugging in the charger, I hear a notable clunk of at least one contactor closing. Then 2 light on the dash show up indicating charging. After a few seconds the lights go out & the battery contactors disconnect. The car will not go to ready mode.

After clearing all codes, these codes are what resets on startup.
C118C 0109
C1A6E 0109
C1A70 0109
P3176 00C0
P311C 00C0


I believe the P3176 to be the most critical code, the root cause of which is my primary concern now.
 
OK, P3176 still indicates a fault with the inverter capacitor array. Are you sure this is not a lingering fault, i.e. can you clear these errors and do they actually disappear when you then re-scan for DTCs?

If not, then there's still something wrong. You say you only hear one contactor - that's not correct. You should hear a CLUNK-a-clunk-CLUNK over the course of 2-3 seconds or so.

The contactors close and open in the following order:

- Negative relay ON (CLUNK)
- [this is where the precharge/positive relay weld check happens]
- Precharge relay ON (very muffled clunk)
- [pause]
- Precharge relay OFF (probably not audible)
- [this is where the precharge relay/resistor open check happens]
- Negative relay OFF (a)
- [this is where the isolation check happens]
- Negative relay ON (clunk)
- [this is where the negative relay weld check probably happens - not quite sure]
- [slight pause]
- positive relay ON (CLUNK)
- Ready mode

You can check the actual relay signals on the VCM connector E62 (see EVC service manual page 88). If the relay routine stops after the precharge part, either your fuse, precharge resistor, HV wiring, something internal to the inverter or precharge relay is broken. The way the car checks whether something is wrong is by checking that the voltage on the inverter capacitors is in some acceptable range. If it's too low, it will interpret this as either the precharge resistor or relay having failed open. If it is too high even before engaging the precharge relay, it will interpret this as a welded relay.

If the complete routine is played out on the E62 connector but you don't hear all the clunks, then you still have a faulty relay.

Hope this helps. If you have any other clues to go on, we might be able to help better.

OH! Really important - it is cold right now, is your 12V battery good? It will sometimes these errors if the battery voltage is below approx. 11.6V and the relay controller refuses to engage the relays.
 
Wow @mux , that is a lot of really useful info. Thank you.

First off, I'm in Maui so cold here has been down in the 50*s Fahrenheit at night; and the 12V battery was replaced by the Nissan dealership just before we bought the non-working car in 8/18. I have charged it regularly low these many months, but I'll charge it again now Since it is resting at 12.36V.

I measured the precharge resistor, and tested the precharge relay with my multimeter and a power probe. I should have tested all the relays when the battery case was open, but I may resort to dropping it again & checking them.

I have cleared the codes from every ECU multiple times. The EV/HEV codes do clear, and stay away a few moments, and after clearing, the battery charge and miles guesstimate show up & the car light blinks a little (equivalent to my Prius ready light I am guessing) before car light goes off, and the codes Return as the VCM is running startup checks.

I like the idea of checking out the HV relay control signals at the VCM to see where it stops, or completes the cycle...

Today I have been going through the Nissan factory service manual and in the P3176 diagnosis flow chart, it asks if P311C is present. It is present, so I moved to that section.

The section on P311C has a bunch of ECU queries for DTC's using Nissan Consult which I do not have, but I do have all the DTC's from LeafSpy pro, and the DTC’s mentioned in the diagnostic flow chart are not present. Finally the manual says replace battery junction box (HV contactor/precharge assembly) which I just did with a “good Tested” unit purchased from Hybrid & EV Battery Supply in Las Vegas. Now I didn’t fully test it myself, I quickly checked that the HV contactors are open, & the precharge resistor is 30.9 ohms, and the precharge relay works.

EDIT: I activated the HV + & - contactors with a power probe from the connector at the battery case. I could hear a resounding clunk from each contactor, although I did not electrically verify the contactors were closed. Next to devise a way to activate both contactors at the same time so I can electrically verify they are closing, ie. CAREFULLY measure if there is 360V or so at the HV connector.

The Manual next says if codes are still present after clearing again, “Replace HV Junction Box”. Now I have another HV JB I bought from a crashed car being dismantled. Also we just bought another complete 2011 “Parts Only” Leaf at the insurance auction, & it moves under it's own power (although it displays I-key fault). Theoretically I have enough parts on hand to get this nice clean, titled car working. I just want to perform the correct tests to ensure I am replacing the right parts, and not making lots of extra work.

On an aside, when I installed the inverter I did not pull vacuum and then Refil the cooling system like I do when installing a Prius inverter. The small coolant reservoirs were filled and although the used inverter was empty, I thought the inverter coolant pump would cycle coolant through the inverter.

EDIT; I just pulled the inverter again to assess replacing the HV JB, & there was still no coolant in the inverter. I wonder if one of the coolant pumps is dead, & that is what damaged the car in the first place; although the Nissan Diagnostic report says they tested both coolant pumps & they both passed the test. The OP of this thread topped up coolant and that solved his issue which had at least 2 of the same codes I am working on solving.

Also the previous owner stated that the car suddenly lost all power while traveling down the road, & upon towing it to Nissan he was told it needed an inverter as the car had P324F Drive Motor A IGBT, P0A1B Drive Motor A control module, & other codes listed previously in this thread. I am guessing that the failed IGBT in the inverter is what welded the HV contactors shut in the first place. The battery was replaced under Nissan Warranty in 2016, & the contactors are the gen 2 type, so the cannot have been more than 2.5 years old at failure.

Hmmmm.... time to stop for the day & try again tomorrow.....
 
Well, I tested functionality of the HV contactors inside the battery case by activating them manually from the connector. With the negative contactor closed & the positive contactor closed I measured 380.1V at the HV cable. With the negative contactor closed & the precharge relay closed I again measured 380.1V with any of them open I measured 0V. Looks like all contactors work, & precharge circuit works too. I guess I will continue on to the next step which according to the 2011 Nissan Leaf service manual is to replace the HV Junction Box.
 
That is basically everything in the HV JB. So it works. I'd be surprised if replacing it will make any difference.
 
mux said:
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....
 
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.
 
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...
 
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.
 
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
 
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.
 
@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
 
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