2015 BMW i3 REX issue - drivetrain inoperable

[Brooks75]

I'm trying to resolve a frustrating issue with my 2015 i3 Rex with 50,xxx miles on it. After 30-odd minutes of running, it'll generally (although not always) throw a drivetrain error. This always seems to happen when coming to a standstill, as the Rex is turning itself off. The drivetrain error will clear after 10 - 15 mins of the car being switched off (or if cleared via OBD), but will then happen again in a shorter period of time. I have professionally had a foreign car specialist put in a new 12v Remy AGM battery, change the plugs & coils as well as replace the fuel pump relay switch.

Still after all that, the REX will start but then I get the warning light above fuel meter on dash and REX disengages. Code that keeps coming back is 11401.

Any help and solutions are greatly appreciated!!

 

[Minotaur]

I have / had similar issues. "Drive Train Error" [ REX I3 2015 ] I phoned up BMW and they said that they cannot see problems. Currently, I am not getting this error but intermittently it occurs. Not a clue why. Nope, I have not plugged in anything to clear error codes etc. Just appears to die out. Now after writing this, I am sure, it will be back to mock me

 

[Houdini56]

I have had drive train error messages.on my I3 Rex for over 6 months..its.drive only in electric with engine light coming on and staying on.plus running out of electric with no way of using a charging station..type 1 plug..i now have a type 1 to type 2 which helps but here in australia its the most random stupid infrastructure for EVs...anyway....after much investigation and diagnostics money and frustration..it was something fairly simple..an 02 sensor needed replacing..dirty or old fuel probably the cause..now at 8kms left of electric..Rex seamlessly purrs into life...aaaahhhh...life is good..i LOVE my I3 again...

 

[hadaR1150R]

I have had drive train error messages.on my I3 Rex for over 6 months..its.drive only in electric with engine light coming on and staying on.plus running out of electric with no way of using a charging station..type 1 plug..i now have a type 1 to type 2 which helps but here in australia its the most random stupid infrastructure for EVs...anyway....after much investigation and diagnostics money and frustration..it was something fairly simple..an 02 sensor needed replacing..dirty or old fuel probably the cause..now at 8kms left of electric..Rex seamlessly purrs into life...aaaahhhh...life is good..i LOVE my I3 again...

Wow, that might be the problem I'm having! Was it the oxygen sensor before the catalyst or after the catalyst?

 

[Andy P]

I've had this happen previously and was told it can sometimes be caused by using a higher voltage public charger - like the ones that give you 80% in 20 mins. I've avoided these and used the medium voltage ones at services or my home charger and that seems to have fixed the issue. Also it happens when the weather is really cold so I make sure I pre-condition before departure and that helps

 

[Dutchi3]

I've had this happen previously and was told it can sometimes be caused by using a higher voltage public charger - like the ones that give you 80% in 20 mins. I've avoided these and used the medium voltage ones at services or my home charger and that seems to have fixed the issue. Also it happens when the weather is really cold so I make sure I pre-condition before departure and that helps

The car communicates with the fast charger so the voltage will never be higher than the car tells the charger to be. So what you are told is not true i.m.o.

 

[Candece]

I fixed this with a fuel pump relay. OEM part $25. Take out glove box for easy viewing. 30 minute fix. I keep a spare relay in the car.

 

[hadaR1150R]

I fixed this with a fuel pump relay. OEM part $25. Take out glove box for easy viewing. 30 minute fix. I keep a spare relay in the car.

I've been wondering where that relay is, thanks. People say to replace it proactively. Will look into doing that.

Can you confirm what your symptoms were that got fixed with new fuel pump relay? My symptoms are that Rex runs only for short period (varies 10 to 20+ minutes) and then when the engine shuts down at a stoplight (normal) it throws the Drivetrain message, electric drive only. Sometimes check engine light comes on. Usually if car is left sitting for a couple of hours the Rex will then run again for a while.

Have been looking into oxygen sensors based on what Houdini56 said above. But if new fuel pump relay will fix it, wow, much cheaper and easier!

 

[alohart]

I've been wondering where that relay is, thanks. People say to replace it proactively. Will look into doing that.

I've read that there's an identical relay plugged into the same board which is up behind the glove box. You could switch the relays temporarily to learn whether that fixes your REx problem without buying a replacement.