pncguy
Well-known member
This is the first I have heard about a problem with a 2015 braking system. Do we know if there was a build date after which it was fixed?
New recall? P5327 for electronic brake boost in cold temps.
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MartinChico
Well-known member
I had this brake recall campaign service performed on my Leaf (at Chico Nissan/Hyundai, Chico, CA) on Wednesday, 11/11/2015. On Sunday, 11/15/2015 I had some sort of catastrophic brake system failure when I was attempting to back out of the garage. I was only able to stop the car via the parking brake. (See this thread: http://www.mynissanleaf.com/viewtopic.php?f=30&t=18283&start=20 )
Surprisingly, this problem occurred on a cool (~40-50 F), rainy day--apparently the conditions that this recall campaign was intended to address!
Surprisingly, this problem occurred on a cool (~40-50 F), rainy day--apparently the conditions that this recall campaign was intended to address!
MartinChico said:
Yeah. After spending more than half my life goofing with computers, I'm pretty firm in the belief that you can't fix a hardware deficiency with a software tweak.
XeonPony
Well-known member
mwalsh said:
Truer words hath not been spoken.
Soft ware is to limp to do any hard work, hence its name SOFT! My car shouted at me 2 days ago about this, I recall what I read here, and I am in no hurry to do it. Rather I'll look into geting a btter relay put in
ElectricEddy
Well-known member
Got the service campaign letter yesterday: " When then vehicle is parked in very cold temperature conditions, the relay inside the electronic brake booster may freeze. If this occurs, when the vehicle is first started, a brake warning lamp illuminates to immediately alert the operator. The brake system continues to function in a special "assist" mode, but may require noticeably more pedal effort." First I have heard of this mode. Wasn't sure where to post this as there are 2 other threads related to this topic : http://www.mynissanleaf.com/viewtopic.php?f=30&t=18283&start=20, and http://www.mynissanleaf.com/viewtopic.php?f=30&t=20770&start=10 . I haven't been to the dealer yet but I am sure it is the dreaded P5327 . I hate to fix something that works, and I don't exactly live in the coldest place in the planet. How many out there have had this done and your location, and any noticeable changes in the cars functions.XeonPony said:
dhanson865
Well-known member
ElectricEddy said:
I did merge one of the two threads you linked to. The other was reporting an issue that may happen with or without the update. That leaves us with
This thread aka http://www.mynissanleaf.com/viewtopic.php?f=27&t=20785 to discuss P5327 for electronic brake boost in cold temps.
and
http://www.mynissanleaf.com/viewtopic.php?t=18283 to discuss brakes failing on power on. Which may be fixed by P5327 or may be a separate issue.
aarond12
Well-known member
I just got the brake notice in the mail today for my 2015 LEAF S. Here's the letter for those interested...
Levenkay
Well-known member
What can software do about a frozen relay?
Hi all. As part of a regular check-up, the local dealer performed the P53270 recall. It consisted of flashing new firmware in. I found it odd that a problem where a relay freezes would be fixed with software. I bet it was cheaper than sealing the relay.
After the recall work was done, plus an additional software update, I noticed that the brakes don't grab as much as they used to, which is a positive. On the downside, "D" mode driving has more aggressive regen which I think is a mistake. I will always get better range by coasting than regening just to try to get the energy back out later. Better range and driving pleasure will come out of having zero regen on decel and should only be applied when the brake pedal is depressed. I know opinions vary on this.
JR
After the recall work was done, plus an additional software update, I noticed that the brakes don't grab as much as they used to, which is a positive. On the downside, "D" mode driving has more aggressive regen which I think is a mistake. I will always get better range by coasting than regening just to try to get the energy back out later. Better range and driving pleasure will come out of having zero regen on decel and should only be applied when the brake pedal is depressed. I know opinions vary on this.
JR
knightmb
Well-known member
Getting mine updated tomorrow, will report back my findings as well.
TomT
Well-known member
About the only thing I can think of is that, below a certain temperature, they cycle it from time to time to keep it from freezing...
Levenkay said:
eddiebo924 said:Had my recall performed today. Had an 8:00AM appt and was out by 8:45. Our guys at Valley Nissan in Longmont, CO are awesome. So no way should it take an hour and a half or two hours.
I'll post back if any brake weirdness is going on.
BTW. . . It's a 2015 with about 19,500 miles. Yes, I drive the crap out of that thing and LOVE every single mile.
Same here, pushing 24,000 miles on my 2015 with 10 months of ownership. People always say I should have leased, but my mileage is exactly why I bought the Leaf. Even with the low gas prices and a car payment I'm saving a fortune.
knightmb
Well-known member
Makes sense, the Leaf knows the outside temperature, can't imagine it takes a lot of 12 volt power to cycle it occasionally.TomT said:
roguenode
Member
JRoque said:
I realize you may not use B-mode, but if you have tried it since the service, did you noticeable changes?
On a side note, I'd also prefer "D" mode have be a coast mode, but as you say opinions vary. I'd also still want a "B" mode with high regen. The ability to chose either as the default mode when moving out of park or neutral would also be nice.
knightmb
Well-known member
I just got the update for my 2013 SV and it has made two major differences (both good in my opinion). The dealer did a software update only, didn't mess with anything else on my vehicle (of course they tried to up-sell some tires, but wasn't interested).
Before, in D mode (no Eco), I could hit 20kW of Regen at 50 mph by just letting go of the accelerator and coasting. The braking effect was less than Eco mode which would hit almost 30kW and B mode which almost always hits +30kW even at much lower speeds.
Now, in D mode (no Eco), I barely kiss 10kW of Regen at 50 mph. I have to be going nearly 70 mph to hit 20kW of regen now. At much lower speeds under 50 mph, it is cut in half again, maxing at 5kW of Regen and at speeds less than 35 mph, regen bare registers 1kW and gives the feeling of coasting the entire way to a stop.
The difference between D mode (no Eco) and Eco mode were nearly half before. I could play with the Eco button at highway speed and watch the regen double or cut in half. Now there is about 75% difference between the two when switching. The new change was strong enough that it felt nearly identical to a fully charged Leaf when no regen is active and coasting is very easy. But my battery was at 25% and I could easily hit full regen by just switching in and out of B mode or Eco mode.
Anyone else out there that has not gotten this update yet, could you post up your experience? I read an earlier post that D mode was getting more regen after the update, but I have just the opposite effect on mine. So examples, like what were you getting for regen on just plain D mode at 50 mph (get up to speed on level ground, just let go of accelerator), or for 35 mph, etc. I am curious to why we seem to be getting difference results and if this depends on model year or something else?
- Brakes are less grabby when parking and just braking in general is smoother.
- D mode (no Eco) has Regen cut in Half, but all other modes are unaffected. Why mention it? Because it now feels like I can really coast in D mode, as though regen is almost not there. I felt the effect as soon as I left the dealer and had to take a couple of laps back and forth on the Interstate to verify what I was feeling.
Before, in D mode (no Eco), I could hit 20kW of Regen at 50 mph by just letting go of the accelerator and coasting. The braking effect was less than Eco mode which would hit almost 30kW and B mode which almost always hits +30kW even at much lower speeds.
Now, in D mode (no Eco), I barely kiss 10kW of Regen at 50 mph. I have to be going nearly 70 mph to hit 20kW of regen now. At much lower speeds under 50 mph, it is cut in half again, maxing at 5kW of Regen and at speeds less than 35 mph, regen bare registers 1kW and gives the feeling of coasting the entire way to a stop.
The difference between D mode (no Eco) and Eco mode were nearly half before. I could play with the Eco button at highway speed and watch the regen double or cut in half. Now there is about 75% difference between the two when switching. The new change was strong enough that it felt nearly identical to a fully charged Leaf when no regen is active and coasting is very easy. But my battery was at 25% and I could easily hit full regen by just switching in and out of B mode or Eco mode.
Anyone else out there that has not gotten this update yet, could you post up your experience? I read an earlier post that D mode was getting more regen after the update, but I have just the opposite effect on mine. So examples, like what were you getting for regen on just plain D mode at 50 mph (get up to speed on level ground, just let go of accelerator), or for 35 mph, etc. I am curious to why we seem to be getting difference results and if this depends on model year or something else?
Nubo
Well-known member
Levenkay said:
A relay is basically a coil of wire that activates an electromagnet and opens/closes an electrical switch. That coil of wire is also a tiny electric heater by default; as current passes through the small resistance generates a bit of heat.
It's not clear to me how this relay is being used, but it's conceivable that it could be made to generate more heat by increasing its duty cycle. Maybe one could even get clever and pass a low-level current through it, or PWM, not enough to trip the switch, but still produce a little heat.
MSELeaf
Active member
The update took over 2 hours at my dealership in Silver Spring, MD. Not too happy about how long it took but the differences in regen are consistent with what others have said: the brakes are less grabby at low speeds and regen in D mode now allows for smoother coasting.
knightmb
Well-known member
Thanks for confirming, I wondered if it was just me or if the update would affect everyone the same way.MSELeaf said:
Yeah, the less grabby brakes makes parking easier. Before, you really had to feather the brakes while parking as the "creep mode" had a lot of torque that if you weren't paying attention, you come in to the parking spot a little faster than anticipated. :lol:
The reduced regen for D mode is actually quite an interesting feeling. I had a chance to do a lot of city / traffic driving today, so I did it all in just plain D mode to get a feel for the difference. Coasting is very easy, and getting high efficiency numbers are easier if you are light on the accelerator. Kind of a "do-it-yourself" Eco mode.