Check Engine Light on 2019 i3s :(

I really am shocked and so disappointed this is still a thing, after plaguing the 2014-2015 i3 and even going on until (albeit less frequently) 2017!

My 2019 i3s Rex has about 500 miles on it. The first week I got it (about 3 weeks ago) I let the battery go down because I wanted to use & try the Rex and put fresh gas in the little tank. Btw, switching from pure electric to the Rex was seamless and I maintained freeways speeds of over 70mph and even shot to 80mph to pass a truck

Fast forward to yesterday (10-4-19), which was a crazy day and non-stop, and I did not have time to let the i3 charge. I had to let the battery die and drive on Rex. Again, it worked great....until it didn't.

About 10 mins into using Rex, a strange warning appeared on the Infotainment screen about the engine not being able to be used and that only electric power would be usable, but the battery was discharged....

I turned my i3 off, and let it sit for a minute. Restarted, Rex engaged perfectly, warning gone from the screen and accessing My Vehicle via iDrive...all systems ok, no warnings, no messages, BUT......check engine light will not go off

Spending about 45 mins last night reading articles from 2014/2015 this was a BIG problem on Rex models (Phantom CEL after using Rex, but no reason and no fault code stored). Our dealer cannot get me in until Tues, but it seems they might not be able to do anything but clear the check engine light. Should I go in or just leave it on? From what I read....there is absolutely nothing wrong with the engine or emission system. Thanks!!

Deutsch100 said:

Btw, switching from pure electric to the Rex was seamless and I maintained freeways speeds of over 70mph and even shot to 80mph to pass a truck

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That's because there is no switching from pure electric to the REx. All i3's are always propelled by an electric motor. When the REx engine starts, its generator adds power to the electrical circuit that supplies the drive motor. At slower speeds, the battery does not need to provide any power. At higher speeds or up inclines, the battery would need to supply some power if the REx generator's output is insufficient.

Thank you Alohaart!

Does anyone know if the Bimmercode app can clear a Check Engine Light. I went to their site and the i3 is supported and I have an OBD reader for BMW...but Bimmercode website talks about nothing but "coding"/changing options.

I would love to just clear this CEL....it is driving me mad seeing it. Thanks!

I think a standard OBD II reader should be able to clear the light. There are apps that use the same adapter. I've not tried to use Bimmercode, as I don't have a REx that might trigger the fault.

FWIW, the check engine fault lamp can turn itself off after awhile, if it no longer sees the same error that triggered it in the first place. It should remain in the memory for diagnostics later one, though.

A normal OBD2 reader will cancel the warning light, providing your reader isn’t a very cheap one that only reads!

I have only ever had one CEL on our MY17 REX when the exhaust gas sensor went awol, the dealer replaced the sensor and both injectors under warranty, that’s the only fault we have ever had in three years.

Thank you so much jadnashuah and Boxbrownie.

I got a very good OBD II reader that was recommended by BimmerCode and BimmerLink. I can clear codes, but I am just afraid if I actually have a fault, then I am just clearing it and the CEL might come back on, if my REX engages. I HATE taking my brand new, only 3 week old car to the dealer...but I am not sure if I have a phantom CEL or an actual issue.

Sadly...I will keep the appointment at my selling & servicing dealer for tomorrow 10/7

When I checked with my OBD II this morning, 10 codes came up, 5 active and 5 pending!! Cylinder misfire, cylinder misfire, evaporative emission and a bunch of others I did not recognize.

Shit! Car is less than 3 weeks old and has about 500 miles on the odo!

Danke schön BMW!! Bayerische Technologie, LOL!!!

As opposed to an ICE where it won't move unless the engine is run, that's not true for the i3. As a result, depending on storage, use pattern, and weather conditions, if something is loose, moisture can get places it shouldn't. IOW, it could be something simple and once resolved, never show up again. You won't know until it's looked at. My use pattern saw no big need for the REx, so I avoided all of those ICE issues entirely. If you need it, you need it, but IMHO, it's best to avoid carrying around an engine that is only used on occasion.

Update from BMW!

Fault codes are showing a fuel tank vent valve!! Seriously?! Wasn't this issue from 2014/2015? I cannot believe this is still going on, 4-5 years after i3 models began experiencing this. SMH!

They said if all parts are in stock, should only be 1 more day.

The i3 is a little (well, maybe a bit more!) weird in that, since the REx isn't run regularly, to help keep the fuel from degrading, the tank is pressurized. That has two issues, one maintaining pressure, and two, releasing it so you can safely open the cap to refill it.

My needs didn't seem to warrant the REx, so I opted to bypass it and bought the BEV version...cheaper, lighter, more efficient, fewer bits to fail. Hasn't been an issue in over 5-years, but that's me.

jadnashuanh said:

The i3 is a little (well, maybe a bit more!) weird in that, since the REx isn't run regularly, to help keep the fuel from degrading, the tank is pressurized. That has two issues, one maintaining pressure, and two, releasing it so you can safely open the cap to refill it.

My needs didn't seem to warrant the REx, so I opted to bypass it and bought the BEV version...cheaper, lighter, more efficient, fewer bits to fail. Hasn't been an issue in over 5-years, but that's me.

Click to expand...

i3 is super weird jadna!! LOL

Thanks Jim!

Car still at the Service Dept. First it was that fuel tank valve, now they are saying it is a "carbon/charcoal" canister.

Car is about 3 weeks old and only has a few hundred miles. 2019 i3S Rex. I am not too happy