Checking interest in an "Auto-B" Leaf mod (gen 2 only)

[BillAinCT]

As others have done, they'll do something to their Leaf for themselves. Maybe others want to as well so they put it here.

In that line, I'm prototyping an "Auto-B" module for the Leaf.

What is it? A very small module you wire between the shift sensor (they call it that) and the VCM.

What does it do? When I shift to D, it will shift the car to B. Many have asked for this default and it's become apparent from my testing B mode is just more efficient. At least for me and I stay in e-Pedal mode. Once B is activated, the shifter is ignored until it sees P, N or R. Then the next D selects B. So if you want to shift back to D you still can. In case the car goes in for service or is sold, this can be enabled and disabled without having to remove it from the car.

What can go wrong? It can fail which means nothing changes - the feature is off. All lines go through to the VCM. It's fused protected for safety but there is no significant load. Liability? I don't see anything - it can't go into D by itself since it has to see "home" (shifter is released) following a shift into D so it's always iin D and no other state. Otherwise it's just watching for that condition. And the state that can enable and disable the functionality (hold in Neutral for 5 seconds perhaps longer based on feedback).

Installation? Pull the front of the black shifter cover up. There are clips on the left and right side. Unplug the 12-pin cable and plug this module into the shifter and cable that was in the shifter into this module.

And that leads to me to ask the subject - is there any outside interest in this?

 

[cornbinder89]

Bill, since no one else answered here is mine:
I like the idea, and if it were done as a "software" option with Leafspy, I'd likely set up the car that way.
But if I'm honest, I wouldn't be as interested in a change in the hardware of the car.
I know that doesn't make a whole lot of sense, but it is where I'm at.

For me driving in "B" mode + eco, is much like driving my semi with a Jacobs retarder. Both slow the vehicle about as fast, so it is something I am accustom to. In that sense I would make it my preferred operating mode. That said, it is easy enough to make the selection manually.
My wife likely wouldn't be a comfortable with it, as it is more aggressive than a "normal" car when slowing.
Not likely what you wanted to hear, but I think it is better than saying I'd be interested and then not following through.

 

[BillAinCT]

Bill, since no one else answered here is mine:
I like the idea, and if it were done as a "software" option with Leafspy, I'd likely set up the car that way.
But if I'm honest, I wouldn't be as interested in a change in the hardware of the car.
I know that doesn't make a whole lot of sense, but it is where I'm at.

Actually I didn't really expect any replies so thank you. I expect the same thinking of not wanting to add something to the car. Since I'm doing it, I trust it. I can see others not being so sure. So it does make sense, even though there are a few posts asking how to default to B mode. I don't think there can be a LeafSpy setting as the VCM is watching (same as my device) for a second shift to D while in D. Had the shift sensor not been a 5V device and so simple I wouldn't have continued once I came up with trying to automate it. I'm retired from the embedded computing field, so this was also for something to do for fun. I'm just testing with a shifter simulator - it has to work perfectly before I install it. There's a small chance the VCM doesn't like it, but I've seen another project where the individual wanted to shift to D when the "gas" pedal is pushed and was successful.

My wife likely wouldn't be a comfortable with it, as it is more aggressive than a "normal" car when slowing.

Using B in e-Pedal mode must be different. I find it less aggressive while finding a larger window where I know it's coasting and not adding regen. In D mode, I found it hard to coast - the coast pedal window seemed very small. I don't recall seeing anyone else say they think B mode in e-Pedal is easier to coast in, but it may be why I see a 5-10% increase in efficiency (which I know is very hard to measure). The fact is I'm often driving for several minutes before realizing to shift again. Which what got me thinking, "Can I automate this?"

 

[cornbinder89]

May be I wasn't clear, mine is a 2015 so no E pedal, just eco mode. Depending on the SOC and temp as well as road speed I see regenerative power in the mid 20's to close to 30 kw. That is noticeable, and goes higher/stays up longer if the brake pedal is lightly applied.
I realize mine is not gen 2, but was commenting on the idea in general, and whether I would consider it.

 

[Learjet]

make sure you have great insurance, if you try to sell that thing.

 

[BillAinCT]

I'm totally guessing that OVMS and CAN bridges can wreak a lot more havoc than this can. Your advice applies there too then.

 

[Learjet]

I'm totally guessing that OVMS and CAN bridges can wreak a lot more havoc than this can. Your advice applies there too then.

Careful encouraging people to drive around in a mode that doesn't use the brake lights, like one would expect. Might want to include that disclaimer.

 

[BillAinCT]

Brake lights work the same in e-Pedal mode in B and D mode. I tested that when I read that on MNL. I don't know what MY that was claimed for, but on my 2022 it works the same. If it's really true for some MY, how that's not a recall when a rear camera that might someday fail is makes no sense.

Edit: I assume you're going to say that it's the case not in e-Pedal mode. I'll test that and take your advice on the warning. Thanks.

 

[cornbinder89]

Several months ago, there was a discussion about regenerative braking and requirements for it to be integrated with the braking system.
Long and short of it is: once you cross a threshold that the Leaf does not, it has to be integrated with the brake so ABS kicks in. Makes sense so you don't get wheel slip on regenerative brakes in bad weather, it also would have brake lights activated.
The threshold allowed on the Leaf is less than this point. so no, the B mode doesn't slow the vehicle fast enough to need brake lights activated.
Learjet's argument is like saying brake light would be required when downshifting and "engine braking" in a ICE car.
The retarding force tapers as the vehicle speed drops, not because the car can't keep it up, but so the effect tapers. If you lightly keep your foot on the brake pedal (activating the brake lights) the retarding force stays between 25-30kw until the speed slows to just a few mph.
In short, a "non issue" with B mode.

 

[BillAinCT]

I've often seen ICE vehicles slow to 5-10 MPH coming to a light where I think their brake lights are both out. Only to find they were able to stop pretty quickly without braking. Maybe they downshifted (steering wheel paddles make that easier) but maybe not. I see many cars on a mile steep downhill ride the brakes and I wonder why aren't they downshifting. I'm at 25-30 kW for almost a minute and usually get 1% back. Which is more than lost on the way up.

 

[bojoho]

Yes I am interested. I can see paying $80 for reliable option for this module.

 

[Auda]

make sure you have great insurance, if you try to sell that thing.

Some countries aren't so anal and really is there any need for your comment ? Caveat emptor and all that.
Yes I'm interested. I've wondered why it isn't a standard option.
the other thing I would like is for it to start with cruse control enabled.

BTW I have disabled all the low speed noises in or leafs.
I find it interesting that way back when you had to have a man with a red flag* walk in front of your car to warn women and horses the a noisy vehicle was coming. Now we can make close to silent cars so they have to make a noise ! Talk about a backward step.

* from Wikipedia
"In the United Kingdom, the law required self-propelled vehicles to be led by a pedestrian waving a red flag or carrying a lantern to warn bystanders of the vehicle's approach."
and
"Secondly, one of such persons, while any locomotive is in motion, shall precede such locomotive on foot by not less than sixty yards, and shall carry a red flag constantly displayed, and shall warn the riders and drivers of horses of the approach of such locomotives, and shall signal the driver thereof when it shall be necessary to stop, and shall assist horses, and carriages drawn by horses, passing the same."