VDC stuck on, re-gen also suffering

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Supernintendo

Member
Joined
Aug 19, 2017
Messages
6
Hello all,

I have a new-to-me 2014 Leaf S with 27,000 miles and 11 bars. It's been running fine since I got it a few months back, but for the last week or so two things started happening:
1. VDC light is always on. I try toggling "VDC Disable" on and off, and that separate "VDC OFF" light goes on and off, but the regular VDC light is always lit.
2. Re-gen only lights up one or two circles, even in ECO mode, no matter what brake pressure I use. All 4 re-gen circles have the double-lines around them by the way. This also used to work fine.

I have checked the brake fluid and it's full. Nothing leaking that I can tell.

I do not have LeafSpy. What should I do?

Thanks
Alan
 
Supernintendo said:
Hello all,

I have a new-to-me 2014 Leaf S with 27,000 miles and 11 bars. It's been running fine since I got it a few months back, but for the last week or so two things started happening:
1. VDC light is always on. I try toggling "VDC Disable" on and off, and that separate "VDC OFF" light goes on and off, but the regular VDC light is always lit.
2. Re-gen only lights up one or two circles, even in ECO mode, no matter what brake pressure I use. All 4 re-gen circles have the double-lines around them by the way. This also used to work fine.

I have checked the brake fluid and it's full. Nothing leaking that I can tell.

I do not have LeafSpy. What should I do?

Thanks
Alan
Check the 12V battery
 
Out of curiosity, are the tires mismatched? Are they all the same size?

Leaf Spy Pro can be used to read the DTCs (Diagnostic Trouble Codes), if any.

If you have any of the 3 year/36K basic warranty left and the tires aren't mismatched, I'd get it looked at, under warranty ASAP.

My wild guesses are the tires, 12 volt or a failed or somehow disconnected sensor.
 
Thanks for the tips. The 3/36 warranty is expired. Tires are all the same size and all look nearly new. Front pair is a matched pair and rear pair is a matched pair, but front and rear are different brands. All 4 are same size and have same minimal tread wear.

I'll check the 12V as well.

What I determined this morning was that brake-initiated regen doesn't seem to work at all. The regen bubbles are purely deceleration based. I can let off the gas and get regen, but brake pressure has no effect.
 
Supernintendo said:
Thanks for the tips. The 3/36 warranty is expired. Tires are all the same size and all look nearly new. Front pair is a matched pair and rear pair is a matched pair, but front and rear are different brands. All 4 are same size and have same minimal tread wear.

I'll check the 12V as well.

What I determined this morning was that brake-initiated regen doesn't seem to work at all. The regen bubbles are purely deceleration based. I can let off the gas and get regen, but brake pressure has no effect.

Your observations are consistent with a wheel sensor (or tire mismatch) problem because the wheel speed sensors do not come into play with regeneration until brake pedal is pressed. Look for broken wires or loose connections associated with each wheel sensor.
 
GerryAZ said:
Your observations are consistent with a wheel sensor (or tire mismatch) problem because the wheel speed sensors do not come into play with regeneration until brake pedal is pressed. Look for broken wires or loose connections associated with each wheel sensor.

Do you mean the TPMS? Or are there some other wheel sensors involved? Search on the forum just keeps returning TPMS results, and the owners manual doesn't mention wheel sensors at all. Thanks again.
 
^^^
Please read the section under Electronic Stability Control of https://jalopnik.com/this-is-how-abs-esc-and-traction-control-work-513807036 or http://auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/electronic-stability-control.htm. VDC is an acronym for Nissan's stability control.

https://www.youtube.com/watch?v=MCRLKRluk1w has some visual aids.
 
Thanks. I get the gist of how ESC works. Only reason I mentioned TPMS was because the only results from a forum search for "wheel sensor" were a million threads on TPMS.

Any advice on how to check these VDC wheel sensors on a '14 Leaf? Owners manual does not mention them and I took a look but didn't see anything that was obviously a wheel speed sensor.

A picture, a location, a visual description of the sensor?
 
^^^
You're best off consulting the service manual (https://www.nissan-techinfo.com/find.aspx?dept_id=10).

To diagnose the problem properly, you will likely need to read the DTCs. I can see some listed relating to wheel sensors on page BRC-57 of the '13 Leaf service manual. Page BRC-45 says
LIGHTING CONDITION
• A malfunction is detected in the VDC function, TCS function, ABS function, EBD function, brake limited slip
differential (BLSD) function, or brake assist function of the ABS actuator and electric unit (control unit).
• For the relationship between warning lamp and DTC, refer to BRC-57, "DTC Index".
 
cwerdna said:
^^^
You're best off consulting the service manual (https://www.nissan-techinfo.com/find.aspx?dept_id=10).

To diagnose the problem properly, you will likely need to read the DTCs. I can see some listed relating to wheel sensors on page BRC-57 of the '13 Leaf service manual. Page BRC-45 says
LIGHTING CONDITION
• A malfunction is detected in the VDC function, TCS function, ABS function, EBD function, brake limited slip
differential (BLSD) function, or brake assist function of the ABS actuator and electric unit (control unit).
• For the relationship between warning lamp and DTC, refer to BRC-57, "DTC Index".

Thank you cwerdna I will start digging into that service manual.

I did purchase a Bluetooth 4.0 LE OBD-II and got LeafSpy Pro, and read the DTCs.

1. Assuming the "Ok" lines are not errors, does this really mean that I have 10 trouble codes present on my car??? Ouch. I wonder how many the car lot knew about and just cleared before they sold me the car.
2. Why do some of the lines have a ">" before them and some do not?

Read DTCs 21

>C1116 0009 ABS Stop Lamp Sw BRC-92
C118A 0108 ABS E-Driven Int Brake System BRC-124
U110D 0108 ABS E-Driven Intelligent Brake Comm BRC-130
Ok None ---> AIR BAG
>B2555 0009 BCM Stop Lamp Circuit SEC-69
C1704 0008 BCM Low Pressure FL WT-26
C1705 0008 BCM Low Pressure FR WT-26
C1706 0008 BCM Low Pressure RR WT-26
C1707 0008 BCM Low Pressure RL WT-26
C1A67 0109 BRAKE Stop Lamp Switch BR-98
>C1A70 0109 BRAKE Brake Control System BR-160
Ok None ---> CHARGER
Ok None ---> EPS
Ok None ---> EV/HEV
Ok None ---> HVAC
Ok None ---> HV BATTERY
Ok None ---> IPDM E/R
Ok None ---> METER
Ok None ---> MOTOR CONTROL
Ok None ---> SHIFT
Ok None ---> VSP
 
These just mean you need to add more air to your tires, they are under inflated:

C1704 0008 BCM Low Pressure FL WT-26
C1705 0008 BCM Low Pressure FR WT-26
C1706 0008 BCM Low Pressure RR WT-26
C1707 0008 BCM Low Pressure RL WT-26

For the rest, I would review these manual for some ideas:

  • http://www.nicoclub.com/manuals/Leaf/2014%20Leaf/sec.pdf (B2555 0009 BCM Stop Lamp Circuit SEC-69)
  • http://www.nicoclub.com/manuals/Leaf/2014%20Leaf/br.pdf (C1A67 0109 BRAKE Stop Lamp Switch BR-98)
  • http://www.nicoclub.com/manuals/Leaf/2014%20Leaf/br.pdf (C1A70 0109 BRAKE Brake Control System BR-160)
  • http://www.nicoclub.com/manuals/Leaf/2014%20Leaf/brc.pdf (for the other DTCs that show "BRC" in the description)

Look also at BRC-10 thru BRC-12, as there is a diagram showing the location of relevant parts. In particular, the location of the VCM, wheel sensors, control unit, etc.

FYI, all the service repair manuals seem to be available here:

http://www.nicoclub.com/manuals/Leaf/2014%20Leaf/

Nice!

As a first step, I would check that none of the cables/connectors have come loose on the key components. As mentioned earlier by another poster, it would be a good idea to check the voltage of your 12V battery as low voltage can cause a bunch of weird issues. If you have a battery charger, then trickle charge the 12V battery, clear the DTCs (using LeafSpy), then see if they reappear with the 12V battery now charged fully.
 
May have to disconnect 12V battery - terminal for 5 minutes ( better : charge it while disconnected to over 12.6V using a standard 12V charger) then reinstall and clear dtc's.
At least that will fully eliminate that possibility.
 
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