Brake failure

[Lothsahn]

Did Nissan EV affairs help you at all?

If this was my car, this is what I'd do:
1) Go to a junkyard and get the brake controller from a wrecked 2013-2017 Leaf. There are a bunch of model numbers. Any of these should work:
https://www.wholesalenissanparts.com/oem-parts/nissan-master-cylinder-460074np3e
https://www.nissanpartsdeal.com/parts/nissan-control-asmy-br~46007-3nf5a.html
https://www.nissanpartsdeal.com/parts/nissan-control-asmy-br~46007-3nf9a.html
https://www.nissanpartsdeal.com/parts/nissan-control-assy-brake~46007-4np0a.html

While I was there, I would ALSO get the ABS sensor 47660-4NA1A:
https://www.nissanpartsdeal.com/parts/nissan-actuator-asmy-a~47660-4na1a.html

If you want new parts instead, you could buy the 4NP3E directly from the first link. It's $1500. You might do the repair and find it doesn't work. if it doesn't, you'll also have to replace 47660-4NA1A, which costs another $1000 new.

2) Install the Brake controller (46007-XXXXX) yourself or go to an independent mechanic/dealer and have the part installed. The dealer is likely more expensive.

3) Clear DTC's via LeafSpy. CAN and Brake codes gone?
a) Yes? Awesome. Continue to 5.
b) No? Install the ABS controller (47660-4NA1A).

4) Clear DTC's via Leafspy. CAN and brake codes gone?
a) Yes? Awesome. Continue.
b) No? You must have a wiring problem on the CAN bus. Check wiring or have a mechanic check and replace wiring.

5) Take the car to the dealer and have them do two things:
a) Reset the Angle Sensor neutral position (BRC-60). This must be done anytime the ABS unit is replaced and can only be done by Consult (dealer tool)
b) Update the brake controller firmware to the latest version, even if your car doesn't show an active recall. The part you pulled may not have the latest brake controller FW.

Firmware updates should run you $150-300. Using Junkyard parts, this whole repair could likely be done for <$1000.

P.S. I see you live in New York. I know a guy in New York that has 5 wrecked Leafs. I don't know if he has these parts, but he'd likely pull them for you for a low cost, if you were interested. He's a great guy and helped me with some hard to find wiring harnesses for my backup camera project.

 

[nlspace]

i would want some evidence or proof that points to the hardware as the problem.

Have you had any brake issues or symptoms such as described by the fleet website, or any real problems or changes in the operation of your brakes?

You have not shown any DTCs that indicate a hard failure in any hardware equipment--all the codes are related to CAN not working properly. But you have used a splitter device to read and send commands on the CAN buss using the OBDII port.

i had a 17-month old Nissan aux battery reading 12.7 that was the ultimate root of my problems. If a trickle desulfator doesn't float at 14.4 then it's not going to be doing any desulfation; floating at a lower voltage just keeps it charged at the float level.

So it looks to me that you have unaswered questions about a possible CAN buss overload, a possible incorrect reset procedure, and possibly the aux battery, in my opinion.

 

[ydrape]

I had a similar brake failure on a 2015 SL in Nov 2017. They had to replace the Motor Room Harness to have the U110D removed during the diagnostic.

The workorder is in French but I think it is a bit «understandable» in English.

https://drive.google.com/open?id=1YWQOMfDDmQeC7DlvRwO77QrcEmXNhdxk

 

[LeftieBiker]

Motor Room = motor compartment?

 

[ydrape]

Motor Room = motor compartment?

Yes. The technician explains that he has to "demount the front bumper cowl top and the complete dash" without a procedure in the service manual. Next, he explains that he has to fix two grounds behind the reinforcement of the dash.

The e-actualor and ABS pump were replaced, but U110D remains. Called Nissan who ask them to also replace the harness.

I am under the impression that maybe, the whole problem was just a ground fault behind the dash. I didn't speak to the technician about that.

 

[LeftieBiker]

Yikes. I'm actually surprised that we don't see more of these 'buried' failures of small components and connections. It's a good thing we don't...

 

[ydrape]

Yikes. I'm actually surprised that we don't see more of these 'buried' failures of small components and connections. It's a good thing we don't...

Hopfully, I was under warranty. They told me "we don't re-install old parts replaced during diagnostic". To correct a DTC, the diagnostic procedure says replace this part. In my case, after near 30 days, Nissan asked them to replace e-actuator, Abs pump and the harness. Everything is OK since that.

 

[Thekuai]

Did Nissan EV affairs help you at all?

still waiting on them. Apparently it is a 3 day review process and approval is on a case by case process. I was told monday or Tuesday the latest I will have a decision. I will keep everyone updated.

 

[Thekuai]

i would want some evidence or proof that points to the hardware as the problem.

Have you had any brake issues or symptoms such as described by the fleet website, or any real problems or changes in the operation of your brakes?

whenever I press the brake pedal It activates abs pump noises at even the slightest brake light activating pressure. If I brake normally, the pedal goes almost to the floor. If I want any braking action I have to push it all the way to the floor as if there is no brake assist. Braking is violent and locks the wheel up almost.

https://youtu.be/KH5dlxDW-mk



You have not shown any DTCs that indicate a hard failure in any hardware equipment--all the codes are related to CAN not working properly. But you have used a splitter device to read and send commands on the CAN buss using the OBDII port.


This is how the tech diagnosed the FTC as per the service manual:




After failure, I removed thensplitter cable and plugged my elm427 bluetooth device directly into the o r2 port to diagnose and attempt to clear dtc's

i had a 17-month old Nissan aux battery reading 12.7 that was the ultimate root of my problems. If a trickle desulfator doesn't float at 14.4 then it's not going to be doing any desulfation; floating at a lower voltage just keeps it charged at the float level.

the 12.7 reading is from the 12v accessory port while the car was in acc mode so there was a load on the 12v battery. The tender floats the battery at 13.7 volts when fully charged and desulphates by the way of a high frequency pulse.

BatteryMINDer Model 1510: 12V-1.5 Amp Battery Charger Maintenance Charger/Desulfator Designed for Cars, Trucks, Motorcycles, ATV, Boat, RV, etc.

https://www.amazon.com/dp/B00Q3CM2QY/ref=cm_sw_r_cp_apa_i_B0i0DbKD4JR58

So it looks to me that you have unaswered questions about a possible CAN buss overload, a possible incorrect reset procedure, and possibly the aux battery, in my opinion.

 

[ydrape]

whenever I press the brake pedal It activates abs pump noises at even the slightest brake light activating pressure. If I brake normally, the pedal goes almost to the floor. If I want any braking action I have to push it all the way to the floor as if there is no brake assist. Braking is violent and locks the wheel up almost.

https://youtu.be/KH5dlxDW-mk

Your description is EXACTLY the brake problem as I had. The DTC U110D and P3195 were also the same for me.

I would be surprised that two parts of the braking system became bad at the same time.

Good luck!

 

[Lothsahn]

BatteryMINDers aren't cheapo desulfators. While anything can be bad, I suspect given both the multimeter reading your battery voltage and the quality of that desulfator, that the battery isn't the issue.

I know nlspace said that you didn't follow a "proper" disconnect, but I would be extremely surprised if leaving the car disconnected from the battery for 15 minutes didn't fully reset everything. I've disconnected the battery on a Leaf many times, and the car has always fully reset after being disconnected for 15 minutes.

ydrape's comments are interesting. It absolutely could be an intermittent or failed grounding connection, or damaged wiring.

At this point, the only way to know for sure is to check wiring continunity (which the tech did, as per the service manual), and then start replacing parts. If replacing parts fixes it, great. If not, you're gonna have to keep hunting. If the parts are $2k and $1k each, I recommend salvage parts.

 

[nlspace]

Did you have the Vehicle Driving Control (skid and traction control system) button engaged when you did this video test?

Are you hearing any chime warning sound when the brake and ABS warning lights show up on the dash?

Do you get any regeneration energy while driving and let off the accel pedal? what about if you lightly touch the brake pedal, can you see regen occur on the dash energy bubbles or the energy level meter of the center console?

In the video i can hear the motor spinning in the brake booster when you press the brake pedal. and it spins back out when you release the pedal.

If the electric-driven intelli brake booster and control unit were defective then it would not operate, AND i would expect to see C118A show up in the list of DTC for the Brakes. You have never shown that DTC.

In the video i hear the ABS pump and actuators clacking and making noise when you press the brake pedal, but you are getting a CAN error for the ABS and not a C118A DTC for the Brake system.

The Consult device has self diagnostic tests for both the ABS and the intelli Brake Booster, which should reveal DTCs for these units if they fail the self check. Yet still no hardware failure codes have been reported.

There is a section to measure power and grounds for the Brake Control System in the BRC manual. It doesn't have a DTC pointer that i could find.

You are also showing the U1000 CAN error in the EV/HEV system and the Body Control Module--i wonder how do those relate to the Brake system CAN errors?

Maybe with 3 levels of CAN errors there really is an issue on the CAN circuits of the control boards, and maybe the only way to change those boards is to replace the entire hardware actuators.

 

[Thekuai]

Did you have the Vehicle Driving Control (skid and traction control system) button engaged when you did this video test?

no, never used that button before

Are you hearing any chime warning sound when the brake and ABS warning lights show up on the dash?

no, then again I have the pedestrian warning module module unplugged so I get no startup sounds and no backup sounds as well

Do you get any regeneration energy while driving and let off the accel pedal? what about if you lightly touch the brake pedal, can you see regen occur on the dash energy bubbles or the energy level meter of the center console?

regen is working as normal as I had it in B mode to help me slow down
In the video i can hear the motor spinning in the brake booster when you press the brake pedal. and it spins back out when you release the pedal.

If the electric-driven intelli brake booster and control unit were defective then it would not operate, AND i would expect to see C118A show up in the list of DTC for the Brakes. You have never shown that DTC.

In the video i hear the ABS pump and actuators clacking and making noise when you press the brake pedal, but you are getting a CAN error for the ABS and not a C118A DTC for the Brake system.

The Consult device has self diagnostic tests for both the ABS and the intelli Brake Booster, which should reveal DTCs for these units if they fail the self check. Yet still no hardware failure codes have been reported.

There is a section to measure power and grounds for the Brake Control System in the BRC manual. It doesn't have a DTC pointer that i could find.

You are also showing the U1000 CAN error in the EV/HEV system and the Body Control Module--i wonder how do those relate to the Brake system CAN errors?

Maybe with 3 levels of CAN errors there really is an issue on the CAN circuits of the control boards, and maybe the only way to change those boards is to replace the entire hardware actuators.

 

[nlspace]

On the video i noticed that the VDC/Traction Control Warning was lit, meaning that there is a fault of the VDC function. There is a second light below the warning to indicate when the VDC is OFF by pressing the VDC OFF switch by the left knee.

Another troubleshooting clue is that the warning chime will sound if there is an error in the power supply for the brake system. Since you have it disconnected then this could lead to a false diagnosis.

What a complicated brake system! Take a simple vacuum operated booster and replace it with a bunch of electronics, pumps, motor and ball-screw actuator and throw in a high speed serial buss for good measure. So when you press the brake pedal, your foot doesn't move the piston, but a sensor sends a signal to a controller to command the motor to spin the ball screw to push the piston Wonder what's the weight savings in all that?

System Description:

 

[Nubo]

...What a complicated brake system! Take a simple vacuum operated booster and replace it with a bunch of electronics, pumps, motor and ball-screw actuator and throw in a high speed serial buss for good measure. So when you press the brake pedal, your foot doesn't move the piston, but a sensor sends a signal to a controller to command the motor to spin the ball screw to push the piston Wonder what's the weight savings in all that?...

Certainly complex. But since the amount of regen available is variable, this is how they "blended" the two braking forces so all the driver has to think about is how much braking they need.

 

[GerryAZ]

Actually, the linkage is such that the foot pedal does apply pressure directly to the master cylinder piston when there is no assist available and the pedal is depressed far enough (much like a typical vacuum assist master cylinder).

Since the error codes, warning lights, and description of sounds/actions match the symptoms I had, I am confident that the problem is within the intelligent brake controller and that the ABS unit is probably OK. I hope Nissan Customer Service will help with the cost since there are several related threads on the forum (all involve 2015 models) so it is not an isolated problem.

 

[Thekuai]

Update: Nissan has agreed to cover 80% of the parts and labor for the brake control unit and abs actuator.

 

[cwerdna]

Update: Nissan has agreed to cover 80% of the parts and labor for the brake control unit and abs actuator.

Yay! Still pricey but obviously MUCH better.

 

[EmilyC]

If he's been properly maintaining his battery and it's reading 12.7v on a multi-meter after being disconnected from the charger for an hour, it's highly unlikely that low voltage is the cause of these errors.

Trying the reset as recommended is a good idea. If the car does begin to function again, take it to the dealer immediately and have the voluntary brake recall done. Once the firmware is updated, the issue should no longer occur. If you don't get the firmware updated, yes, it can occur again.



Yes, if you have a true issue with the CAN bus (broken/shorted wires, etc), then replacing the brake controller won't fix it. However, it's very possible the CAN bus errors are caused by the malfunctioning brake controller. Remember, this is very likely a device attached to the CAN bus that has a corrupted firmware causing erratic behavior.

I also don't believe you should replace the ABS unit. I believe the entire failure is in the brake controller or VCM, and replacing the broken part will magically "fix" the ABS unit when the CAN issues are corrected.

I still encourage you to give me a call so I can answer any questions you may have in real time. There are also options to fix your car far cheaper than the $4600 quoted.

I have the exact same issue, same fault codes, same loss of normal braking function with my 2016 leaf.

Dealer wants 5000 to replace the brake unit? Do you have any tips or advice?

 

[EmilyC]

Yay! Still pricey but obviously MUCH better.

Did it work? Did it solve your issue?