Car doesn't switch over to REX.

[PVEVman]

Hi,
my I3 REX is my commuter and I've been using it for about 2 years. My daily drive is about 70 miles and so far I was very pleased with it. The solar panels on my roof cover more than the daily charge so I'm driving for less than a penny a mile, fuel wise that is. However, lately the switching over to the REX didn't go so well. I don't need it a lot but it is crucial to me that it works. After the battery was almost empty, the carrot turns white, I would loose power and after doing 30 mph on the highway for 15 minutes, the REX finally goes all out and all is good. The BMW dealer found 3 errors in the electric motor and advised to reboot the car with updated software, it 'only' costs you $550.-. They were 99% sure that it would solve the problem. So I had it done. However, yesterday, I needed the REX again and it didn't do anything, even the carrot didn't turn white. Now I know you can hack the software so you can get the "European" version which means that it will show more fuel in your tank and you can start the REX manually. This might be a good solution because I don't have a lot of faith in the dealer. My guess is that they are going to change out control modules until they fixed it and I have to pay for each and everyone of them. Does anyone have the same experience as me? I would like to point the dealer in the right direction, or maybe just the software hack.
Thanks,

 

[i3Houston]

Its best to hack just the range extender option, its pretty easy cost about $50 for both app and dongle.

On longer or unknown journeys i often kick Rex around 30% or higher so if it fails there is some juice to left to develop plan B

 

[Adoi3]

Hi, might be a completely different scenario, but I had a issue that the Rex wouldn't start when cutting over you'd get a Drive Train error message which was semi intermittent for a while with a switch off sorting or sometimes it would just start whilst you limp along. Took a while to identify but turned out to be the fuel pump. ( I had let the fuel go dry a couple of times knowing I was a couple of miles from home and the last bit of electric would suffice. I guess if no petrol the petrol pump doesn't lubricate when turning and may have shortened it's life) Once replaced never had the issue again.

 

[PVEVman]

OK, so it is supposed to be fixed now, although I haven't tested it yet. I'm not sure if I want to and then being towed home again. The car was at the dealer for 3 days and they tested the battery on a cell by cell basis. The head mechanic said that the battery and the software needed to be calibrated, because the control unit "thought" there was more battery left than was actually the case and thus did not turn on the REX. Now, after the software update it did indeed showed that I could drive for a 98 miles, which I knew was kinda optimistic for a 5 year old, 45k miles BMWi3. Of course, when I dropped it off with an empty battery, so they could test it for themselves, the damn REX would start right up the next morning as soon as they got in. Anyways, I think I need the app and the dongle. Which app is it and where can I get "the dongle"?

 

[alohart]

Anyways, I think I need the app and the dongle. Which app is it and where can I get "the dongle"?

The app is BimmerCode. Tested dongles are listed here. Dongles are available from Amazon.

 

[eNate]

... the control unit "thought" there was more battery left than was actually the case and thus did not turn on the REX.

Dang man, some EV owners are worried about getting ICE'd out from using a charging station, but I never really considered getting BEV'd out from using the REX! That's a new one.

 

[jadnashuanh]

I'm not positive on the REx, but the other BMW ICE vehicles won't actually run the tank dry just for the reason indicated...the pump is lubricated by the fuel, so no fuel, the pump will die. IOW, there should always be some fuel left in the tank when it stops.

 

[Cris]

Hey there, I guess the option to reduce the amount of KMh electric range before the rangefinder kicks in seem to have disappeared from the BimmerCode features list. Is this still adjustable?

 

[jadnashuanh]

https://bimmercode.app/cars/i3/ You need to enable the range extender menu. Once that is enabled, on iDrive, you can set when you want the REx to turn on. Note, 2017 and newer i3's already use the full fuel tank, so there's nothing to adjust. This goes back to a California rule about using their HOV lanes...the fuel-assisted capacity cannot exceed the pure BEV range...in 2017, with the larger battery, that became a mute point.

NOte, the i3 is what is referred to as a serial hybrid...IOW, regardless of whether the engine is running, the vehicle is always running on electrical power. A serial hybrid is one that can run on each motor independently, or in combination. For now, the i3 is the only serial hybrid car you can easily buy, but there seem to be at least one more coming (I think the Mazda is a serial hybrid with a Wankel engine). The REx is approximately a 34-Hp motor...the i3's electric motor is 170-Hp...that's why, if the battery isn't full enough to fill in and you put a heavier load on it, it will slow down...When was the last time you drove a vehicle with a 34-Hp engine? Maybe never...try to climb a hill or overtake with any gusto, and forget about it if you can't augment it with the batteries.

Make sure to get an OBD-II adapter that Bimmercode supports, and there are some differences, depending on whether you're using ANdroid or iOS.