Understanding How To Use Leaf Spy Pro error codes

[nlspace]

A new aux battery sitting on the shelf at the auto parts store may read 12.8, but is not fully charged as seen by it dropping to such a low reading. Sounds like a good charging session is needed to de-sulfate the plates from the over-discharge.

With the CAN buss not working (possibly due to low aux voltage) there can be no DCDC converter action taking place to recharge the aux.

sounds like a fun project, good luck with getting it working

[GaleHawkins]

Thanks nispace. It is a great project. First objective is to understand what is going on to cause these codes. After we started watching this 2015 SV auction we saw the same lost of display data on our 2016 SL that is setting striped of bent sheet metal. We connected a charger and all the data returned. We took a new battery that was on a charger/desulf box for 3 days hoping for the same results but no dice.

The old gear head in me has mental stress parting out a 5 year old 27K mile car in mint condition inside and out. I hate unknowns so I have spent a lifetime turning unknowns into knowns. If this car has the critical braking failure the parts may just cost too much. Our 2016 was totaled and just the needed parts from Nissan was $13,000. Our 2016 SL had no technical issues before the guy ran the red light so getting it back on the road is Job #1.

Seeing our 23 year old son drilling down on the issues with this 2015 SV is exciting. In part I got our 2016 Leaf to teach the son and his twin sister about EV's but I did not expect her to total it. She and her mom are recovering OK so we are learning more about EV issues than planned. If the traction battery Died Hard the car is only good for parts. If we can prove the battery is very healthy selling it will help offset our cost to rebuild our 2016 SL. I love the 4 cameras since I have no spine or head movement but the 2020 150 mile range battery makes it a keeper.

[nlspace]

It sounds like you are an old timey troubleshooter so i'm sure you will figure it out.

If aux is known to be good, and verified as such, then i would pull every fuse and relay and clean the contacts and give it a try maybe one at a time if finding the root cause is important; or just pull and clean them all, then try if it doesn't matter which circuit is the culprit.

i wouldn't start pulling brake modules and such until you get basic 12V functionality back working, although there is a big 12V capacitor module in the e-brake system that pulls a big slug of current everytime it has to recharge.

i revived a "dead" 2012 that the dealership said had a bad main pack; their troubleshooting is limited to strictly reading DTC codes and following the steps--no out of the box thinking allowed.

My b-g twins are only 18 and she drives the laef now; he would drive an EV if it were a Tuskla.

[GaleHawkins]

Boy-Girl twins can get interesting at our house we learned.

Growing up on a cash free farm in the 50-60's I learned troubleshooting from my Dad. As an AT in the Navy in the 1970's I got to attend A and B electronic schools in Millington TN. In the 90's I got into building and servicing of personal computers before moving to software development.

I have told the son we are going to step through the fuses first.

What did you find wrong with the Leaf you mentioned?

[nlspace]

A weak and worn out OEM aux battery (only 17 months old).

The car had been towed to the dealer service dept, and evidently they didn't even think to check the aux or give it a charge. Car was towed back to the owner and dumped in their driveway--they wanted out and quickly sold it cheap. i put in a new aux and drove it home.

[GerryAZ]

Can you use the function in Leaf Spy to read the ID codes/version numbers for all of the modules? If so, it would indicate that the individual modules are at least somewhat functional. In looking at your DTC code list, it is not clear to me that there is any communication from the LBC (lithium battery controller, aka BMS for battery management system) that is inside the battery case. Also, most of the errors in your list are consistent with a weak 12V battery. Don't worry at all about the steering angle sensor calibration error (AV-88 or U1232 0108) because that will clear after the car is successfully started and the steering wheel is turned lock-to-lock a couple of times. It is due to loss of memory in the audio/video system due to weak 12V battery.

Just to reiterate--I doubt there is anything wrong with the intelligent brake controller and master cylinder so don't do anything more than temporarily disconnect the connector for testing. I just mentioned it because it is a rare, but know issue on 2015 model year Leafs and the original unit in my 2015 intermittently caused CAN Bus communication errors which required 12V battery disconnect along with Leaf Spy DTC code clearing to restore normal operation.

[GaleHawkins]

Thanks. Tomorrow my son is going help do some troubleshooting with a hot battery.

Leafspy does report two bits of information besides those codes. One is the odometer miles and the voltage of the 12v battery as it discharges at a fast rate after the start button is depressed. The blue tooth doggle flashes like crazy so it is live.

Not even one of center blue charge lights burn. If traction battery is truly dead then it shot I guess. The old 12v battery was flat. The insurance claim was filled 4 months ago.

Tomorrow maybe we'll get more bits of information. LSP is showing some battery voltages and temps . I haven't figured how to blank that screen to make sure it is valid new data.

The fast discharging of the 12v battery means there's a massive 12v load somewhere. I will get a charger on the 12v battery as we test like you said.

[GerryAZ]

If you mean the 3 blue lights on the top of the dash in the center, then I don't expect them to light unless an EVSE (or DCQC) is connected and there is appropriate network communication. Again, no bars on the display in front of the steering wheel is due to lack of CAN Bus communication. Also, substantial discharge current from 12V battery during startup is normal--you normally don't see it because DC-DC converter takes over quickly. Good Luck tomorrow!

[nlspace]

It sounds like it might be worth putting a clamp-on current probe on the aux battery to measure this high current draining load. It is not normal to discharge a new or full battery just by pressing the start button, and a high discharge could be pulling down the 12V supply buss across all the ECUs and preventing boot up and operation.

Using the current probe along with pulling fuses one at a time might reveal the culprit drain circuit.

[GaleHawkins]

What modules does LeafSpy have to be accessing to display VIN, odometer and # of L1 L2 charges,?