Weird Braking issue

[IslandDriver2024]

2014 SL.

I've been living with this for a while. When I am at very slow/parking lot speeds the brakes will lock up on me and the car will slide. I've gotten very used to it and can compensate for it by very gently feathering the brake pedal when I'm at the threshold where it happens - but it's definitely not safe and a problem. It's super sketchy when going down wet hills. I've had a couple times where it felt like the brakes were just gone momentarily. My partner wisely refuses to drive the car.

Over quite a few months It hasn't gotten any worse or better. I've tried unplugging the 12v, replacing the 12v, the braking reset procedure (TC off and stand on brakes for 30 seconds). I brought it to a couple mechanics who basically just said they couldn't figure it out because they don't know about EV's. I brought it to Nissan dealership and they wanted to replace the whole master brake cylinder (part is discontinued and very expensive on ebay).

When I google I find people resetting the brakes having success but that's done nothing for me.

I've got some codes:
C1107-00 08 ABS FR RH Sensor-2 BRC-68
C1A7-01 08 Brake Brake Control System BR-160
P3177-00 08 EV/HEV ECU Activation Err EVC-242
U1266-02 08 Multi AV TCU Conn AV-92
>U1A08-00 0B TCU Tel Antenna No Conn AV-201

Anybody here have any ideas? I have absolutely loved this car and don't want to give up on it.

 

[danelo]

That first code C1107 is for the ABS speed sensor. I am thinking it is the front passenger side sensor. I would take the wheel off and see if there is any damage to the wiring or the sensor.

 

[cornbinder89]

I agree, fix the wheel sensor 1st.
Generally when looking at DTC's, start with the ones highest up on the list, solve those and record the rest, clear and see what comes back.
You might have an ABS problem or a brake master control, but 1st clear the sensors from the list.

 

[nlspace]

Do you ever hear any strange noise under the hood when you press the brake pedal--like binding or creaking in the master cylinder?

Open the hood and have someone press, hold, and release the pedal, repeat this several cycles both slow and fast rate, while you listen at the master with a mechanics stethoscope, or put your hand on the housing to feel for vibration.

On What island are you driving, and what is the general humidity level there?

[edit: the DTC codes are just listed alphabetically by the subsystem involved, not by any priority. Any CAN Buss or supply power related codes would stop the car from operating and be high priority. For example P3177 is a code that would cause the car not to charge or go to READY mode]

 

[cornbinder89]

[edit: the DTC codes are just listed alphabetically by the subsystem involved, not by any priority. Any CAN Buss or supply power related codes would stop the car from operating and be high priority]

Not according to the Service manual.
Chasing your tail looking for a CAN Bus code when the main problem is a sensor or dead input will not be helpful.
Once you clear the 1st code in the system reported, it is very likely the CAN bus will work.
Codes were "numbered" in a order for a reason. CAN get the prefix U for a reason.
in this case the wheel sensor code is the lowest alpha-numerically and may be the root cause. Address it 1st.
In this case the U codes are for the TCU, are your seriously suggesting these will shut down the car? You can pull the TCU and not effect the car!

 

[IslandDriver2024]

Thank you all so much for the feedback, sounds like I should take a look at/replace the sensor and go from there. Thanks also for the interesting discussion.

Do you ever hear any strange noise under the hood when you press the brake pedal--like binding or creaking in the master cylinder?

Open the hood and have someone press, hold, and release the pedal, repeat this several cycles both slow and fast rate, while you listen at the master with a mechanics stethoscope, or put your hand on the housing to feel for vibration.

On What island are you driving, and what is the general humidity level there?

I'm in the Caribbean so very high humidity and heat. (I lose about 4% SOH every year and I'm down to 58% but all the cells are still good and the island is small so range still hasn't been an issue.)

I haven't heard any strange noises from the master cylinder and I would have thought if that was my issue, as a mechanical issue, it would have gotten worse or changed after some time. Symptoms popped up out of nowhere and haven't changed at all, which makes me feel like it's more likely a computer/sensor issue. I'll try listening with a buddy though.

 

[IslandDriver2024]

Another question on this. It looks like I need this part 47910-3NA1A OEM price is ~$220, RockAuto has BECK/ARNLEY version for ~$100, and then I'm seeing other options for way less on RockAuto and Ebay as well. Is this the kinda of part one can cheap out on? Just two wires, looks pretty simple.