2016 LEAF 12v battery replacement - won't start

[ironmanco]

My oem 12v battery finally bit it this morning and I replaced it with a fresh interstate battery. Now I can't get the car started.

details:

-new 12v battery tested good with battery tester
-traction battery SOC 80%
-have tried disconnecting + terminal for 1, 5 and 10 minutes
-confirmed with LSP that traction battery is at 80%
-display says battery (traction battery) is very low - it's not

Any ideas?

 

[Stanton]

Doesn't make sense...so need more info.
What were the circumstances around the old 12v battery dying? Sudden/gradual/fuse?
Did you replace the battery yourself? If not, did you watch who did it (not something anyone would normally do, but you never know)?
The only other option is try another/different 12v battery.

 

[ironmanco]

Doesn't make sense...so need more info.
What were the circumstances around the old 12v battery dying? Sudden/gradual/fuse?
Did you replace the battery yourself? If not, did you watch who did it (not something anyone would normally do, but you never know)?
The only other option is try another/different 12v battery.

Woke up in the morning, tried to start the car to check soc. Said 73%. Shut car off. Loaded the car with my stuff and went to start it back up and all kinds of things going on. Kind of knew the OEM original 2016 Nissan 12v battery was living on borrowed time so went and got a fresh interstate 51R battery. Tested it before putting it in with a automotive battery tester. All good. Pulled the old one out, put the new one in. And it still won't start. Display says "battery very low" - which refers to traction battery. It also shows the image of the foot on the brake, indicating that it doesn't think I have my foot on the brake. All accessories work (radio, lights, ac/heat, etc).

DTC read:
Ok None ---> ABS
B142A-16 08 AIR BAG
Ok None ---> BCM
C1A62-01 08 BRAKE Control Mod Pwr Supply BR-53
Ok None ---> CHARGER
Ok None ---> EPS
Ok None ---> EV/HEV
Ok None ---> HVAC
U1000-00 08 HV BATTERY CAN Comm Circuit
Ok None ---> IPDM E/R
Ok None ---> METER
P0A8D-00 08 MOTOR CONTROL 14v Power Supply EVC-132/TMS-63
P3247-00 08 MOTOR CONTROL Drive Motor A Inverter TMS-91
P1895-00 08 SHIFT Motor Speed TM-82
P189D-00 08 SHIFT
U1000-01 08 TCU CAN Comm Circuit
B13D9-8F 08 TCU
Ok None ---> VSP

 

[Stanton]

That helps a bit: I'm pretty sure you just need to try another/different 12v battery. This one is "bad" for whatever reason.
You can pretty much discount whatever codes you are getting (including the dash) if you don't have a good 12v; that's just the way EVs are.
If you report back with results/updates, the forum can continue to help.

 

[ironmanco]

The 12v was fine (the replacement that is). I disconnected the battery leads overnight and then first thing this morning connected them back up and the car started perfectly. I didn't even clear the existing codes. As previously mentioned, the new battery tested perfectly (topdon battery load tester) and the old one was definitely shot.

Anyway - I guess I just didn't wait long enough /shrug.

 

[GerryAZ]

Low voltage on the 12V system can cause CAN Bus communication errors (which is what you have in your list of DTC's). It can sometimes take clearing DTC's using LEAF Spy Pro, disconnecting the good 12V battery, reconnecting the 12V battery, clearing DTC's, and repeating the process two or three times to get everything on the CAN Bus restored to normal. Leaving the new 12V battery disconnected overnight allowed the computer modules to completely reset themselves so the car started after reconnecting the 12V battery.

 

[Lothsahn]

Also, make sure you clear codes now that you have the new battery. Codes often don't disappear on their own, so those low battery codes will mask any problems with your new battery.

 

[ironmanco]

Also, make sure you clear codes now that you have the new battery. Codes often don't disappear on their own, so those low battery codes will mask any problems with your new battery.

Actually, there are a lot of DTC codes that do clear based on service cycles (various systems that have sequences that demonstrate the fault is no longer an issue). DTC's (because saying DTC codes is redundant ;-) typically fall into 3 categories for their trigger

- persistent (they need to be manually cleared)
- self-clearing (they will clear based on a service cycle(s) of the system that triggered them
- stored codes (the fault condition clears but you they remain stored as a DTC that was previously triggered)