Brake unit internal shorted!?

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TLeaf13

Member
Joined
Oct 23, 2017
Messages
15
Back story (See "too long; didn't read" below for summary): About 6 months ago I bought a 2013 Leaf. It was showing just one bar missing so I thought the battery was decent. I had purchased the Konnwei OBDII that was the only one recommended by LeafSpy. I plugged it in during the test drive and received iKey errors and failure to pair. It was useless, but I bought the car anyway. About 10 days later, it lost a second bar, and four months after that it lost another (so it's down to 9 bars). I was upset with the rapid degradation and ended up getting the BAFX 34t5 OBDII from here: https://smile.amazon.com/dp/B005NLQAHS/_encoding=UTF8?coliid=I3EY08GZEQ358Y&colid=1E803RI4QZNDV

It worked immediately and I was able to see that the battery is at 70%. Anyway, I had read that it was generally okay to leave these plugged in to log data with LeafSpy. So I left it plugged in, but ended up not driving the car for a couple days. The 12V battery died, so I disconnected it and hooked it up to my 12V battery charger. When it was finished, I hooked it back up and started the car. Both the yellow and red warning lights were on as were the Brake, ABS, and VDC lights. I started backing out and as soon as I pressed the brakes, strange noises came from the front of the car and the brakes only worked when pressed almost all the way down.

Luckily the regen braking was working so I drove in B mode to slow the car down faster. I noticed when first pressing the brakes there were sounds that made me think of laser guns, then about half way down horrible grinding sounds were made (even when in Park mode; not moving), and finally when the pedal was almost all the way to the floor, braking softly kicked in.

A few days later I spent over $120 for a diagnosis from the dealer. They had the car for around 7 hours and this is what they came up with:

Diag. Used consult. C1A61 Current code motor power supply. Checked fuses OK. Electrically driven int brake unit harness and connections OK. 12V present to module. Brake unit internal shorted due to suspected surge. Rec replacing 12V battery and unit. Further testing may be needed.....Estimate to replace 2817.00 parts and labor. Part is from the factory.

So I took it home and did some research. I pulled the fuses for the VDC, ABS, and TCS as shown in http://www.mynissanleaf.com/viewtopic.php?f=38&p=508531#p508531 All the warning lights were still on, but the horrible noises were gone. I put the larger VDC fuse back in and the awful noises returned. So I pulled it out and put the other two fuses back in. The noises are gone, but the brakes are still very soft and warning lights are still on. Sometimes when opening the driver door, different strange sounds can be heard.


TL;DR: 12V Battery died with OBDII plugged in, now the brakes suck. The dealer wrote, "Brake unit internal shorted due to suspected surge" as the diagnosis.

My questions:

- What did I do to my car?
- Am I really going to have to fork out $2,817 to get it (maybe) fixed? (the "further testing may be needed" worries me)
- Did leaving the OBDII device plugged in ruin some electronics in my car?
- Any thoughts from the Leaf community about this?
- Is my car hosed?

I don't have anywhere near $2,817 to spend for this repair and will keep driving it in B mode with soft but functional brakes.

Thanks for any input!
 
I can't say it's impossible that a surge occurred, but it seems more likely that something else is wrong. First you want to fully charge the 12 volt battery with an external charger. Then clear the codes and see what happens. Also, it appears you are the victim of a BMS reset. You were sold the car under possibly fraudulent circumstances. That's another can of worms to open...
 
Thank you for the response, LeftieBiker. I'll give that a try. I may end up replacing the battery as my tester indicates it is a "Marginal" battery.

Also, I would not be surprised at all if I was sold the car under fraudulent circumstances. The "dealer" I bought it from seemed shady and sold only Leafs. He might do that reset with all Leafs he sells. He also only had one key fob, so I'm guessing he sold the other one. I really like my Leaf but am very sad that it's already breaking down.
 
Here's hoping that the brake issue is just a weak 12 volt battery. As for the reset, you might try small claims court, to recover the difference in retail value at least. The problem is getting a legal entity to recognize the value of LeafSpy readings.
 
Replace the 12V battery. A) you buying it and replacing it is cheaper than the dealer doing it, and B) they were going to do it already if you OK'd it. You've already said it needs to be replaced based on your tester.

My 12V battery failed this morning (hoping), but when trying to jump it, I pressed brake pedal when turning on the car, no pedal, all the way to floor. A 12V on the fritz can do weird things to cars. I've seen it before in ICE cars, and then again this morning on my Leaf.
 
Brake unit noise will go away with a good, well-charged 12-volt battery once you get all DTCs cleared. It may take several attempts to clear codes with LEAF Spy and it may require disconnecting the 12-volt battery. Clear all DTCs possible with LEAF Spy, disconnect 12-volt battery for a few minutes, reconnect battery, and clear codes again. Repeat this process until you have no error codes present and your brake issues should be gone. I have had error codes cause the brake unit to go into the mode you describe a couple of times and found bunches of DTCs for CAN Bus communication, brake system, ABS, etc. each time. Since I always have LEAF Spy running when driving and I leave the Bluetooth unit plugged in (unless parking for extended time), I cleared all DTCs and the car returned to normal.
 
Thanks for your replies! I bought a new battery today and followed the steps GerryAZ discussed. I have cleared the codes, disconnected the new battery for a few minutes and tried clearing the codes again. I did this 4 or 5 times. There are always two codes that won't go away in LeafSpy. They are:

C118A 0109 ABS E-Driven Int Brake System BRC-124
C1A61 0109 BRAKE Motor Power Supply BR-46

I had put the fuse back in for the VDS before attempting to clear all the codes. However, the horrible sounds described in my first post persisted whenever I pressed on the brakes. So after trying multiple times to clear all the codes, I decided pull that fuse back out.

It seems the 12V battery wasn't the problem this time, unfortunately. Any other ideas? Maybe the Brake Motor Power Supply is shot and that leads to the ABS E-Driven Int Brake System problem? I am at a loss and I absolutely do not trust the dealer. I would hate to have to take it back to them.

Thanks again for all your replies! Any other suggestions are appreciated!
 
eBay has a booster. https://m.ebay.com/itm/2013-Nissan-Leaf-Power-Brake-Booster-Master-Cylinder-New-OEM/151357960100?fits=Make%3ANissan%7CModel%3ALeaf&epid=1329662948&hash=item233da32fa4%3Ag%3AurMAAOSwQaJXRBRT&_trkparms=pageci%253Aea00b183-bddf-11e7-82a3-74dbd1801314%257Cparentrq%253A702ccfe415f0a990b7d710f1fffb3321%257Ciid%253A9
 
The brake unit noises with the VDC fuse installed indicates that it has power and is somewhat functioning (pulsing hydraulic pressure to at least some of the brake calipers). I would look for problems with sensors, wiring, etc. associated with the ABS and VDC systems before replacing the expensive brake unit.
 
These might help you puzzle this out:

http://www.nicoclub.com/manuals/Leaf/2013%20LEAF/BR.pdf
http://www.nicoclub.com/manuals/Leaf/2013%20LEAF/BRC.pdf

If you end up taking it to a dealer to troubleshoot, I would bring along printouts of the relevant sections matching your DTCs. Hopefully it's just a power harness that's come loose
 
Thank you GerryAZ and alozzy! I will spend some time with those PDFs and see if I can figure something out. I also made a video of the sounds the car makes. I can post it to YouTube if anyone thinks hearing the sounds would be helpful or is just curious. There are also buzzing noises nearly every time I open the driver door, which is where my video begins.

Hopefully I'll be able to track down the problem using the information and resources you two have provided. Those PDFs look like they could be quite helpful. I'll post the video if anyone is interested and report back when I've had time to troubleshoot this. Thanks!
 
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