"Drive moderately. Apply additional braking when necessary. Consult nearest service center."

[808Pants]

That was my center-screen alert earlier today. It cleared on its own after about ten minutes.

If this isn't spurious, then does it indicate pads, fluid, or... that the car doesn't appreciate my normal driving style?

 

[mojo]

It seems like it's telling you that regenerative braking might not be working correctly (without actually using those words, which some users wouldn't understand)? Was your battery SOC at 100%? We know that regenerative braking doesn't work as effectively until there is space in the battery for the regen energy to go (and the car is supposed to use the friction brakes instead to compensate) - but I've been in that position on my car many times, and never seen that message.

If you don't intend to take it to a dealership for diagnosis, you may need to have a look at it yourself with Bimmerlink (or similar) and see if any DTCs have been logged?

 

[808Pants]

It seems like it's telling you that regenerative braking might not be working correctly (without actually using those words, which some users wouldn't understand)? Was your battery SOC at 100%? We know that regenerative braking doesn't work as effectively until there is space in the battery for the regen energy to go (and the car is supposed to use the friction brakes instead to compensate) - but I've been in that position on my car many times, and never seen that message.

If you don't intend to take it to a dealership for diagnosis, you may need to have a look at it yourself with Bimmerlink (or similar) and see if any DTCs have been logged?

Thanks Mojo. SOC was moderately high, but not nearly full up. A month or so ago, I was again wondering about what you're describing - I then had it up to 136 miles after re-genning down the long volcanic slope known locally as the "Saddle Road," between two volcanoes on the big island of Hawaii. The next morning I continued down the slope and had no similar complaints...IIRC the available miles kept going up until we ran out of "downhill."

I *do* need to connect again - haven't done so since I exchanged a WIFI dongle for a wired ethernet version, having found the WIFI was objectionably slow. And yes, I'm very late in forking over the $50 or whatever for B-link. Gonna get on that within the next few days.

But I've also never change fluid or inspected pads (fluid level is OK, at least). 47K miles, as I recall.

 

[mojo]

I'm in a similar position with Bimmerlink - got Bimmercode, but not needed to check any codes, yet...

If you're on 47k miles I would be tempted to changed brake fluid or at least have it tested for water content. If for no other reason than to reduce the chances of corrosion within the brake system components.

I don't think the message can relate to worn pads -- if that is the cause, I'm fairly sure that the car displays a more specific message than the one you are seeing.

 

[alohart]

A month or so ago, I was again wondering about what you're describing - I then had it up to 136 miles after re-genning down the long volcanic slope known locally as the "Saddle Road," between two volcanoes on the big island of Hawaii.

That's a pretty long descent. I don't know what the maximum regen power is, but it might be the same as the maximum propulsive power, 125 kW although it doesn't feel that strong. In propulsive mode, 125 kW can be maintained for only 30 seconds before something begins overheating (maybe the uncooled motor rotor) at which point the propulsive power is reduced to 75 kW. In regen mode, even if less than 125 kW, maybe similar overheating occurs eventually at which point regen braking power is reduced. The warning tells you to use the friction brakes more than expected. However, why would the message recommend consulting a service center when normal operation would return upon cooling as it seems to have done in your case? Oh, well, it's fun to guess.

I *do* need to connect again - haven't done so since I exchanged a WIFI dongle for a wired ethernet version, having found the WIFI was objectionably slow.

What have you used with a wired Ethernet connection? I know of ISTA, but I don't believe that BimmerLink works with a wired Ethernet connection. Having used ISTA a bit with its wired Ethernet connection, the OBD port or the electronic modules in the car might be the speed bottleneck, not transmitting the data via WiFi or Ethernet.

 

[Dutchi3]

We know that regenerative braking doesn't work as effectively until there is space in the battery for the regen energy to go (and the car is supposed to use the friction brakes instead to compensate) - but I've been in that position on my car many times, and never seen that message.

I now live on top of a hill, and the regen works fine going down the hill -without use of the friction brakes- when I leave with 100% charge (which is in reality less than 100% due to a top end buffer). I rather think that you have less/no regen when the bms decides that the pack is too cold to receive full regen at higher charge levels. In other words, it is probably temperature dependent how regen at full battery behaves. In Holland, when the temperature was close to freezing, on a flat road the friction brakes would assist in the first mile, when the battery was at full charge. The regen power is limited to 50kW, which corresponds to the max. DC fast charge power. The difference is that full regen is available even with a full battery, while in a DC charging situation the power is tapering off when exceeding 80% charge. So at what temperature do you experience this behavior? The motor and electronics have no issue delivering a constant power of 50kW even under sustained periods, as the nominal power of the motor is 75kW.

The only thing that is strange to me, in the situation described here, is the displayed message. Never saw that one, even when the car had limited regen due to low temperature.

 

[mojo]

So at what temperature do you experience this behavior?

Not particularly cold at all. I really only notice it a short distance from my house, where there is a steep(ish) downhill section. I think I know when the car is substituting friction for regen, because I hear a scraping noise at the back where the disks are slightly rusty, even though I'm not using the footbrake. Last time I noticed it, the temperature was probably around 15 degrees (so a few months ago now).

But... I might be wrong, and attributing a noise from somewhere else as brake noise. And it probably does it at other times, but I don't hear because it's cold and I have the windows wound up!

 

[808Pants]

I now live on top of a hill, and the regen works fine going down the hill -without use of the friction brakes- when I leave with 100% charge (which is in reality less than 100% due to a top end buffer). I rather think that you have less/no regen when the bms decides that the pack is too cold to receive full regen at higher charge levels. In other words, it is probably temperature dependent how regen at full battery behaves. In Holland, when the temperature was close to freezing, on a flat road the friction brakes would assist in the first mile, when the battery was at full charge. The regen power is limited to 50kW, which corresponds to the max. DC fast charge power. The difference is that full regen is available even with a full battery, while in a DC charging situation the power is tapering off when exceeding 80% charge. So at what temperature do you experience this behavior? The motor and electronics have no issue delivering a constant power of 50kW even under sustained periods, as the nominal power of the motor is 75kW.

The only thing that is strange to me, in the situation described here, is the displayed message. Never saw that one, even when the car had limited regen due to low temperature.

Thanks, Dutchi3 - but "cold" to us here in Hilo means low 60s F. Interesting angle, though. I'm gonna have to watch and see if it recurs, but timing for observations isn't great, since visiting bro means we had to rent a larger vehicle through the holidays while the i3 sits forlorn in the garage. Perhaps it will learn its lesson.

I'd been thinking that every possible warning/advisory/etc had been catalogued and discussed here, but apparently I found one that's not made the rounds. This leads me to wonder: wouldn't BMW have something akin to a glossary of these messages for just this kind of event? I mean, my i3 didn't author that warning; some engineer did, so it seems it must have been intended as the "then..." part of an if/then statement.

 

[808Pants]

That same warning came back for another ten minutes at the tail end of my wife's Xth driver's-license road test, but she was more freaked out about it than the examiner was. (I'm not allowed to answer questions as to whether she passed, anyway...)

I have not yet been able to connect to check for codes because I returned the Bluetooth OBD connector... I'd been thinking that the RJ45-ended cable I'd long ago purchased instead (but never used) would let me use my laptop, vs smartphone, for diagnostics. An RJ-45 adapter for lightning/iphone connection is enroute. But /is/ there a means to use PC for this vs smartphone - eg apps for PC use? During the holidays I've not had a lot of time to research.

Art, I think you once asked after my choice to return the Bluetooth-equipped connector in favor of a cable version, which I made in the interest of reported speed. I'd hated the long delays I'd seen while initially trying the Bluetooth version but had long since lost track of the internet site that convinced me to change connections... and I just ran across the link that steered me to a cable. I need to watch the whole thing again.

 

[alohart]

I have not yet been able to connect to check for codes because I returned the Bluetooth OBD connector... I'd been thinking that the RJ45-ended cable I'd long ago purchased instead (but never used) would let me use my laptop, vs smartphone, for diagnostics. An RJ-45 adapter for lightning/iphone connection is enroute. But /is/ there a means to use PC for this vs smartphone - eg apps for PC use?

BMW's ISTA Windows app is the most comprehensive diagnostic software. It works with an OBD to RJ-45 Ethernet cable but not wirelessly AFAIK. I'm not aware of other apps, but then I'm not a Windows user. I doubt that any macOS apps exist.

Art, I think you once asked after my choice to return the Bluetooth-equipped connector in favor of a cable version, which I made in the interest of reported speed. I'd hated the long delays I'd seen while initially trying the Bluetooth version but had long since lost track of the internet site that convinced me to change connections... and I just ran across the link that steered me to a cable. I need to watch the whole thing again.

I have used a Vgate iCar 2 OBD to WiFi adapter for ~7 years. I initially chose WiFi over Bluetooth because WiFi could potentially have higher bandwidth than Bluetooth. I couldn't find any specs, so that's just a guess. I have noticed that establishing a WiFi connection is slower than with a typical WiFi hotspot or base station, so the adapter electronics are probably pretty low-end and cheap.

Thanks for posting the URL of the video! It's good to know that BimmerCode and BimmerLink can be used with an Ethernet cable at faster speed. I have an Ethernet (RJ-45) to USB C adapter that I use with ISTA on a Windows partition on my 2016 Intel MacBook that has a USB C port but no Ethernet port. I could run BimmerCode or BimmerLink on my MacBook Air either natively (probably won't work without a license) or via iPhone mirroring while connected to our i3's OBD port with an Ethernet cable and my Ethernet to USB C adapter. However, that's a lot of hardware and not as convenient as using an iPhone with an OBD to WiFi adapter, but I need to try this in the interest of science. I don't use BimmerCode, BimmerLink, or eFlow enough to justify buying a RJ-45 to Lightning adapter, and my drawer of useless ancient cables and adapters doesn't seem to contain what I would need.

 

[808Pants]

It's taken until last night, somehow, for me to get connected to the i3, with the intention of checking - at last - for error codes, specifically something that would explain the now-almost-always warning message about "Apply additional braking when necessary," which is something that really need not have been communicated to me, honestly. Now that the screen is virtually constantly hijacked by that message, it's become its own hazard, because I have to keep acknowledging it in order to get the rear-view camera image back!

Anyway, I'm connected via ethernet to my Windows PC now, finally having sprung for Bimmercode. But as with both BimmerLINK and -CODE as tested on my iPhone, there just doesn't seem to BE any diagnostic section of the software! Both start off by locating nine ECUs, which will be great if I want to customizing my coding, but that's clearly not my main concern right now.

I've emailed Bimmercode to get their assistance, but I can't be the only one who has stumbled into this, can I?

The other piece of data I've been less concerned about in connecting is that often, picking out some random ECU and "opening" it to see what those most-basic coding options are, I'll get a message of "unable to code" or some such. I've no doubt that I'm really ethernet-connected: with no action other than clicking on "connect" on the software, the dash turns on (radio, blower, and I think parking-lights, which is a little annoying, but at least tells me there's SOME kind of working connection.) But diagnostics are nowhere to be found.

If anyone happens to have the key to this, please LMK ASAP, since I'm going to be leaving the car here for some weeks later today and would really like to know what I'm in for before I get on a plane...

Thanks - Dave

 

[alohart]

Anyway, I'm connected via ethernet to my Windows PC now, finally having sprung for Bimmercode. But as with both BimmerLINK and -CODE as tested on my iPhone, there just doesn't seem to BE any diagnostic section of the software!

I have licensed the iOS versions of both BimmerCode and BimmerLink. Only BimmerLink scans for diagnostic trouble codes (DTC's). It displays DTC's stored in info memory and error memory, and displays permanent DTC's. However, the current BimmerLink iOS version scanned only 5 electronic modules in a 2014 i3 recently whereas it scans 25 electronic modules in our 2021 i3. I don't understand why because BimmerLink scanned many (all?) electronic modules in our former 2014 i3. It can pretty useless if it doesn't scan all electronic modules.

BimmerCode only modifies the values of parameters that govern behaviors and can't be used to diagnose problems.

Both start off by locating nine ECUs, which will be great if I want to customizing my coding, but that's clearly not my main concern right now.

Your i3 has ~25 electronic modules, so many aren't being scanned. I wonder whether the BimmerLink/Code developer is testing it on old i3's. BimmerLink/Code supports so many car models that he can't possibly test all models with every system software version. You might have to download an appropriate version of ISTA to diagnose your i3.

 

[808Pants]

Art - Thanks yet again.

Ugh. This isn't the first time that AI has screwed anyone, but it's MY first:
"To retrieve error codes using Bimmercode, connect your OBD adapter to your BMW, open the Bimmercode app, navigate to the "Diagnostics" section, select the relevant module (like engine or transmission), and then read the stored error codes; you can also use the "Live Data" feature to monitor sensor values in real-time to help diagnose issues. "

I'll try again (next time I'm in prox to the car!) with that ISTA download. Is the particular torrent that worked OK for you still up on some server?