abs traction control no drive

Got 2 codes that will no clear first is >P3195 000B EV/HEV Can Error EVC-272
Second is >U1000 000B EV/HEV Can Comm Circuit any ideas at to what they are

CAN Bus communication errors associated with the EV system control module, as I suspected. Basically, something interfered with data traffic on the computer network that connects all of the modules in the car together. Disconnect your 12-volt battery for a minute; reconnect the battery, then read and clear the codes with Leaf Spy Pro. If that does not clear everything, disconnect the battery for 5 minutes and try clearing the codes again.

JPDean, did clearing the codes fix your issue? I have a 2015 Leaf currently stuck with the same kind of symptoms. Pushing brake pedal makes pulsing / grinding sound like ABS activiating. The car will go into drive but just starts drifting back as I’m parked on a slight slope. I’m hoping to try Leafspy in a bit and see if I can clear the codes before resorting to a tow.

Thanks!
Bill

Jpdean said:

...codes that will no clear first is >P3195 000B EV/HEV Can Error EVC-272
...

Click to expand...

The P3195 is not a CAN Buss error, it is just an error message that is transmitted over the CAN buss from the so-called "intelligent" brake module.

The likely issue is in the electric motor-driven master cylinder actuator, either the screw mechanism, the feedback signals or the controller. A clue to this is the excessive brake pedal travel going to the floor as was mentioned in an earlier post.

I think there is a thread in the engineering section "grabby brakes" with some technical details of this actuator and its big-assed discharge capacitor. Instead of using a vacuum pump with reservoir, the laef uses an electric motor with capacitor, to provide the additional brake pressure for the master cylinder function.

Is the capacitor just for energy storage? Why not just use one of the batteries?

CAN Bus errors can cause loss of communication between ABS, stability, and brake controllers. The communication errors can cause these symptoms even without actual hardware problems. Clearing DTC's and disconnecting/reconnecting 12V battery a couple of time may clear the issues so try that before replacing expensive components.

My experience is that brakes still work if the pedal is pressed hard enough and far enough (may seem like it is going to the floor) even though the pedal pulses. Also, a weak 12V battery can cause these issues. See other threads for more details.

https://photos.app.goo.gl/NToaF8p1usTHZJcZA

I tried to clear the codes with Leafspy and they kept coming back. Tried disconnecting the 12v battery for a few minutes, a couple of times, but the codes kept returning. So I ended up getting it towed to the dealer. As far as I know they still haven’t looked at it yet.

goldbrick said:

Is the capacitor just for energy storage? Why not just use one of the batteries?

Click to expand...

Failsafe. In case power delivery is compromised, the unit can still function autonomously.

Dealer was able to get codes to clear and got car back into it’s normal state. The service advisor said to think of it as a glitch in the computer..

They said their database showed that other Leaves with this issue had the brake module replaced to fix the problem. They said if the codes come back that’s what I should do. Quoted $1000 for part and $2000 for labor.

Keep the 12V aux battery fully charged using an external charrger if necessary, a weak aux can cause many issues with the car's control units such as the "intelligent" brake module.

I like the quotes around intelligent, lol... I bought a new 12v battery yesterday and installed it, hoping that fixes these issues.

Did you fully charge the battery before or right after installing it? If not I strongly suggest you do so now.

LeftieBiker, I did not. The car sat for about two days and then I used it and charged it. What can happen if I don’t charge before/after changing the 12v battery?

Thank you

The Leaf has a reputation for sometimes not keeping the 12 volt battery well charged. It isn't an issue for everyone, but if yours doesn't, then installing an undercharged new 12 volt battery will result in a chronically undercharged new 12 volt battery. IOW you can get the exact same scenario but with a good battery.

My Leaf that had the brake failure in March acted up again yesterday. I made a video this time.

https://youtu.be/8VpKaaOJ06I

Have you tried disconnecting/reconnecting the intelligent brake unit?
Possible pin fitment/ oxidized connections. Inspect/clean with contact cleaner.

No, but i will give that a try.

I drove the car home yesterday in the impaired state, parked in my garage and charged it, expecting to take it to the dealer today. When I turned it on today the problem was gone.

Maybe ask dealer to test for intermittent connections since probably need to have 12v disconnect before any inspection/cleaning.

Do you have a voltmeter? Use it to check on the voltage of the 12V starter battery, especially if the brake fault occurs--that is the time to measure the voltage level and determine if it is related to this fault for you.

Had your car sat without operation for several days/week before this last episode, or was it an extremely hot weather day?

It seems to be intermittent with aux battery voltage since it did not occur after charging, but that is where measuring the voltage would provide proof.

Unfortunately I didn't have a voltmeter with me when the failure happened. I believe the car was used two days prior so wasn't sitting too long. It was a very hot day, maybe 90-92 degrees in PA, so maybe that affected the battery charge?

Another note is I used the carwings app to run the AC right before the incident happened. I haven't done that in a while. But I used it a few weeks ago without incident so it was probably a coincidence.

The dealer has the car now and they are going to investigate. It drove there fine, no brake issue.. I'm not sure what my options are since there is no official recall on the car. I really don't want to pay for a new brake module out of pocket...