REX Won't turn on

rsmccraw · Jun 11, 2017

Just bought a '14 REX, driving it home from the dealership I depleted the battery, expecting the Range extender to come on. As it got lower and lower it eventually limited me down to 40mph. The left side where the gas range is listed turned blue for a moment before turning grey again. The range extender did not turn on ever to my knowledge. I did not hear it or feel it kick on.
It had sat on the dealers lot for a while before selling to me, could this be something where it had sat too long? The car is still under factory warranty until Dec 2018

Im really excited to get back into it, but I'm just worried somethings wrong with it that wont be covered under warranty?

Anything I should look into or be aware of? Thanks for any help!

bwilson4web · Jun 11, 2017

rsmccraw said:
Just bought a '14 REX, driving it home from the dealership I depleted the battery, expecting the Range extender to come on. As it got lower and lower it eventually limited me down to 40mph. The left side where the gas range is listed turned blue for a moment before turning grey again. The range extender did not turn on ever to my knowledge. I did not hear it or feel it kick on.

Where is the car now?

Can any lights be turned on? If not, it suggests the 12V battery died.

rsmccraw said:
It had sat on the dealers lot for a while before selling to me, could this be something where it had sat too long? The car is still under factory warranty until Dec 2018

The BMW i3-REx warranty coverage has been very good to me.

rsmccraw said:
Im really excited to get back into it, but I'm just worried somethings wrong with it that wont be covered under warranty?

Anything I should look into or be aware of? Thanks for any help!

Contact BMW and follow their instructions. My understanding is they will arrange to tow the car to the dealership who can work up the problem Monday. Towing is a little tricky because the parking brake actually locks the rear wheels.

Bob Wilson

rsmccraw · Jun 11, 2017

Hey Bob thanks for getting back with me so quickly.

BMW towed my vehicle for me to the dealership nearest my home. I guess I will need to wait till monday to hear anything.

The lights still operated, I was able to put the car in neutral. I believe I may have just had the door open not allowing it to drive, though the range extender was for sure not coming on and the screen was telling me I had a low battery and it needed to be charged to prevent damage to the battery. I believe that the i3 could have moved under its own power but I don't think it was worth damaging the batteries over, as the REX was not coming on at all to charge.

bwilson4web · Jun 11, 2017

rsmccraw said:
. . .
BMW towed my vehicle for me to the dealership nearest my home. I guess I will need to wait till monday to hear anything.

You're in good hands.

rsmccraw said:
The lights still operated, I was able to put the car in neutral. I believe I may have just had the door open not allowing it to drive, though the range extender was for sure not coming on and the screen was telling me I had a low battery and it needed to be charged to prevent damage to the battery. I believe that the i3 could have moved under its own power but I don't think it was worth damaging the batteries over, as the REX was not coming on at all to charge.

Sounds like the 12V was working, good!
Door open is a little confusing. I've had the seatbelt occasionally block closing but I always drive with the belt on.
If the car got home, I would have tried using the portable charger but for you it is a new car. I think you can download the Owner's Manual but certainly it makes sense to search for YouTube training videos. In particular, how to use the stalk to cycle through the different information displays.
File this under 'lessons learned', but the web site www.plugshare.com can identify charging stations along your route. If the REx does not come on right away, divert to the nearest L1 or L2 charger with a J1772 connector or fast DC charger with CCS. A last resort, 120VAC outlet since I've found them to be 'unreliable.'
One of the reasons I like the BMW i3-REx is the quality of battery management. I suspect it is unlikely the car will let you damage it. Liquid cooling is an important feature compared to the early Leaf problems with air-cooled.

GOOD LUCK!
Bob Wilson

CCJ · Sep 13, 2017

bwilson4web said:
rsmccraw said:

. . .
BMW towed my vehicle for me to the dealership nearest my home. I guess I will need to wait till monday to hear anything.

Click to expand...

You're in good hands.

rsmccraw said:

The lights still operated, I was able to put the car in neutral. I believe I may have just had the door open not allowing it to drive, though the range extender was for sure not coming on and the screen was telling me I had a low battery and it needed to be charged to prevent damage to the battery. I believe that the i3 could have moved under its own power but I don't think it was worth damaging the batteries over, as the REX was not coming on at all to charge.

Click to expand...

Sounds like the 12V was working, good!

Door open is a little confusing. I've had the seatbelt occasionally block closing but I always drive with the belt on.

If the car got home, I would have tried using the portable charger but for you it is a new car. I think you can download the Owner's Manual but certainly it makes sense to search for YouTube training videos. In particular, how to use the stalk to cycle through the different information displays.

File this under 'lessons learned', but the web site http://www.plugshare.com can identify charging stations along your route. If the REx does not come on right away, divert to the nearest L1 or L2 charger with a J1772 connector or fast DC charger with CCS. A last resort, 120VAC outlet since I've found them to be 'unreliable.'

One of the reasons I like the BMW i3-REx is the quality of battery management. I suspect it is unlikely the car will let you damage it. Liquid cooling is an important feature compared to the early Leaf problems with air-cooled.

GOOD LUCK!
Bob Wilson

To add to Bob's list... Plug share also has an app for your smart phone

imran · Feb 21, 2018

Same thing happened to me, I could hear the rex turn over but not start. after 3 attempts, the car showed a drivetrain malfunction error. Fortunately, I was not far from home so I made it back with remaining battery.

It has been at the dealership for almost 2 weeks now. So far, they have replaced fuel pump, O2 sensor and exhaust manifold gaskets but its still not fixed.

slac10 · Jun 20, 2018

Hello There! My first post here.

I have the exact same problem with my 2014 REX not turning on. It tries 3 times and the I get the error message.

But every other day it starts and works just fine!

The check engine light is on and I looked at the faults with my OBD2 reader: "Misfire on both cylinders"

Any news on your recent problems and what was the cause?

Thanks from Canada.

Steve

Polot · Jun 22, 2018

Возможно необходимо заменить свечи зажигания

Zwerius · Sep 5, 2018

Same problem overhere.
The dealer told me the fuel pump should be replaced (€700,- !!)
But after replacing it yesterday, they're still searching because obviously the fuel pump didn't cause the problem....
So, car is 2 days at the workshop already, without any results so far.

slac10 · Sep 19, 2018

@Zwerius, do you have any update??

Zwerius · Sep 19, 2018

Yes I have an update now.
I've got the car back yesterday after 2 weeks (!!) at the dealer.

They exchanged the fuel pump and the relay belonging to the fuel pump.
However this did not solve the problem.

After a long search, they found out, that the relay of the fuel pump is next to another relay.
And although the exchanged the relay for the fuel pump (according to the dealer documentation from BMW and even a BMW instruction movie for the mechanics), it turned out that the relay next to the supposed fuel pump relay, was the actual fuel pump relay.
So the position of the fuel pump relay was wrong in the official BMW workshop documentation and in the BMW-instruction movie for the mechanics!!

So this could very well be the reason that similar problems in oter i3-REX BMW's could not be solved.

slac10 · Sep 19, 2018

@Zwerius, thank you very much for the feedback! could you scan the paper work or part numbers that needed to be changed that would help my mechanics find or diagnose the problem.

If you can PM me those informations that would be greatly appreciated!

Thank you very much!

Zwerius · Sep 20, 2018

@slac10:
Sorry, but I don't have partnumbers or any paperwork.
I just told you what the mechanics told me.
I didn't even see any of the parts. No idea where they are in the car.

slac10 · Nov 5, 2018

@Zwerius,

It was the fuel pump relay on my car too! Glad you gave me the hint!

I replaced it myself saturday and now it's running fine.

Thanks,

Steve

Polot · Nov 8, 2018

slac10 said:
@Zwerius,

It was the fuel pump relay on my car too! Glad you gave me the hint!

I replaced it myself saturday and now it's running fine.

Thanks,

Steve

Where is the fuel pump relay?

slac10 · Nov 9, 2018

If you visit this website you find a video showing the exact location of the fuel pump relay behind the glove box.

https://www.newtis.info/tisv2/a/en/i01-i3-rex-hat_201404/components-connectors/plug-in-comb-type-solder-connectors/connectors-from-k/k12-1b-k12-1b/1VnXgPAOvC

The easiest way to get to it is to remove the glove box (6 or 7 screws) it is the relay on the right.

Part number: 61366915327

sjjhr · Apr 2, 2019

-I've had 2 "Drivetrain Errors" intermittently since November 2018 on my Dec 13 REx. 1"you can continue your journey", then always before the end of the journey "electric range only, go to BMW I-service". My local non-BMW garage said there were "HV Cable Resistivity" faults in the stack.

-I took the car to a UK BMW dealer, who replaced the injectors and pre-cat NOx sensor and reprogrammed the car

-the new BMW software is buggy, and causes the charge indicator to get stuck to the left even when accelerating

-the 2 Drivetrain Errors returned

-took it to another BMW dealer who diagnosed fuel pump relay and HV cable

By now, I doubt all BMW dealers because I don't see why replacing the injectors and NOx sensor would cure the HV Cable problem.

We'll see what happens and I hope it's just the relay now.

RJackson · Nov 28, 2019

I had the same issue on my i3. Rex would cut out or not start. Diagnostic tool stated exhaust sensor fault so took it to BMW which was my first mistake. BMW just charged €160 to confirm what a standard OBD2 diagnostic tool with tell you. They wanted a further 7 hours of investigation time at €160 per hour to check some of the sensors and wiring. At that rate I expect BMW to know what the fault is. Anyway I took the car back and did not authorise service. You can check the oxygen sensors easy as the sensor plug is on top of the engine and clearly there was no fault with the sensor. So after typing in the symptoms and reading the helpful information above it's likely a fuel pump relay issue. Sure enough it only €15 on an official BMW fuel pump relay and and it takes approximately 5 minutes maximum to install, so it seems silly not to take a chance and just replace it. Sure enough the engine is running perfectly again now. Had to use beamer code software to reset the engine fault light, as your standard pro torque software doesn't work on the i3.

GeraintB · Jan 18, 2020

Thanks to everyone who suggested a fuel pump relay as the cause of an O2 Sensor fault code.

Our REX petrol engine was reporting a "Drive Chain error" and would not run. On checking with a fault code tester, the Fault code was "O2 Sensor not correctly fitted".

Attempts to run the engine in maintenance mode seemed to suggest it was trying to start (cranking a couple of time) then bring up the fault. AN O2 sensor clearly made no sense.

On reading this forum I purchased a fuel pump relay (the right hand sky blue one; Part number: 61-36-6-915-327). On fitting that, and switching on the car, I immediately heard the fuel pump running for about 3 to 4 seconds.

Oddly when trying the maintenance test on the REX the car reported "battery too much charge" despite it being at about 69%. However, on road testing and switching to 'maintain charge' , all worked just fine.

One point; if you have a right hand drive model (ours is Japanese market model), unless you have multiple joints in your right arm and eyes in your finger tips, you need to expect to get very frustrated trying to replace the relay, as the German design engineers must have been having a laugh when they decided to place them behind the ventilation trunking! I used a mirror to confirm the orientation of the other relay before attempting for the fifth time to aline the new one with its socket.

Nanz1 · Mar 9, 2020

Thank you all so much for the help.
I too had the same issue as previous posts and I am happy to report this thread saved me an expensive visit to the dealer. True enough it was the fuel pump relay.
Fault codes read the same oxygen sensor issue and mis-firing.
I cleared them using an Veepeak OBD adapter and a free app.
I paid just under £20 for the relay and it took me just over an hour to fit, this included removing the glove box.
My aim now is to fire REX up at least once a week, to keep the relay from sticking.

I am a happy owner once again.

REX Won't turn on

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