Check Engine Light on REX

Hello,
I need some help on this problem. I know it has been an issue for REX. I got my REX a month ago and I haven't had a chance to use my range extender until today. For the first time, I used it and the check engine light came on. It disappeared once but it came back on when I drove it a few hours later. Mine is 2014 model. I asked the dealer about this and they seemed to have no idea and just told me to bring it to check. What would be the best and quickest way to fix this problem?

Thanks.
Nam

What was the error message that should have been displayed when the check light comes on? Probably you can't do anything about it, only the dealer who should be able to trace the fault.

BrianStanier said:

What was the error message that should have been displayed when the check light comes on? Probably you can't do anything about it, only the dealer who should be able to trace the fault.

Click to expand...

Isn't there a fault engine code issue that is fixed by firmware?

But check that gas cap was tightly closed by whoever filled it last, I just made that error in another car recently.

nkcho said:

Hello,
I need some help on this problem. I know it has been an issue for REX. I got my REX a month ago and I haven't had a chance to use my range extender until today. For the first time, I used it and the check engine light came on. It disappeared once but it came back on when I drove it a few hours later. Mine is 2014 model. I asked the dealer about this and they seemed to have no idea and just told me to bring it to check. What would be the best and quickest way to fix this problem?

Thanks.
Nam

Click to expand...

There is a recall on the pressure sensing switch inside the gas tank. Mine has been fixed.

There are a number of issues that can cause the CEL. The general consensus is that if the only thing you see is the CEL, then its probably OK to just keep driving. Most of the CEL issues are resolved with the March software update. If yours is an early 2014, then you might have the pressure sensor issue which will be fixed under warranty.

Like others have said, this can be caused by various problems. I had it recently on my 2014 REX about 5 months into ownership and the 3rd time I'd used the REX. The dealer diagnosed as a faulty fuel tank isolation valve and it took them a few days to get the part and replace.

Thank you for the advise. I hope mine is related to the latest software update because mine is 2014 model. I got it in late May and confirmed with the BMW genius who had a training session with me several times if the software has been updated to avoid this CEL problem. He said that the software is the most recent one and he has never heard of it surprisingly. I just trusted him but I guess it wasn't true. I think I will need to call them again and let them know about the March firmware update!
I will post later my experience. By the way, my car runs just fine

I'm also having CEL issues with my 2014 i3 Rex. Everytime I use Rex = CEL on. I have an OBDII reader and the code is PO440 (Evap Emissions Control System Malfunction). Gas cap seems tight. Fuel is fresh. Software is reportedly the latest. No codes written to the key fob. Status check says all systems OK. Dealer seems clueless about this fairly common problem. Taking it in next week to let them have a closer look after I use up the fuel to activate Rex. Only had the car since 28 June and this is the 3rd time for CEL. Frustrating. Any ideas?

If you fill the gas tank too close to the top this will happen. It will reset after you have driven it a little and lowered the gas level. Turn off and open the gas tank and close and the light goes away. Lesson is do not fill tank too high.

I got the dreaded check engine light last week, but more importantly our Rex i3 would not start; fortunately at home. Called BMW and was told they would recover the car. A flat bed arrived within two hours and a loaner car (new BMW118i) a couple of hours later. Good going as we live some 70 miles by road (or 30 miles via ferry) from the e-dealer in Glasgow.

The job took 7 days. Combined with the repair (said to be fixed by software update), five “quality enhancements” were installed in the car (March 2014 delivery, 1700 miles):
Replace torsion splined shaft
Program control units
Replace E-transmission actuator
Retrofit backrest stop pad of rear seat
Retrofit package slide/tilt sunroof sealing measure

The car ran fine on the run home. Retardation appeared to be unaffected by the update as some have reported, but have not found any display yet of the state of charge in the instrument cluster.

Clive C

Assuming the SOC is in the s/w for your country, try cycling through the functions with the stalk button on the left stalk. If it's there, it will become obvious...it's not in a dedicated, always on position, it's one of the display options (like temperature).

Thanks Jim.

Not in the options.

Clive C

Pretty sure I've read that the SOC display is a BMWNA feature, and isn't available outside the US (maybe Canada?).

Yes - SOC is displayed below speed on my Canadian model - as is estimated remaining kilometres. I don't think it's possible to turn it off - never tried - can't imagine not wanting it there.

There's a difference between the BEV and the REx, the BEV did not originally have a SOC % readout. Personally, the exact percentage doesn't really help me much, but hey, it's only s/w, enough people complained, and it was easy to add. The old squeaky wheel syndrome. Doesn't always work, but it does sometimes.

Hello, we purchased a 2015 REX in March with about 24k miles on it and now it has 27k, we really have fun driving the car as it is so smooth. Last week the Check Engine light came on so after reading the Forum I am assuming it could be fuel pump related for the REX. The car is still under Factory Warranty and is Certified so I have made an appointment at the closest BMW dealer (not where we bought it) for almost a week from now. My question is can I drive the car with the light on and just charge very day as my round trip commute is about 40 miles. We obviously drove it home with the CEL on. Hopefully the Forum folks will agree with me that it can be driven. Thank you for your time.

Any other warning messages?
If nothing coming up like 'reduce speed' or other cryptic messages not to drive it and to contact your dealer immediately, you should be fine. In fact the check engine light may reset itself and go off after a day or two, then re-appear if it is a continuing fault. But definitely something to have the Dealer check.

Hi, thanks for your response and I have an update. I decided to use the car and on the third start the CEL went out and a text "Service June 2019" or something like that plus a depiction of a car very briefly appears. This all disappeared and comes back with each start so far. As I said I have scheduled an appointment for next Saturday (9/7) and will proceed to that appointment. I will try to contact the Service Department but these days it seems to be quite a project to talk to an actual Service Advisor unlike just a few years ago. I will keep the car charged and hope for the best while using it.
Thanks again for responding!!

That 'Service Reminder' is normal, and will pop up to remind you of pending service. In the U.S. the Rex is scheduled for one oil change a year, one brake flush every two years. My 'in service date' (when the car is first sold) was March 2016 - as it was a service loaner or demo vehicle before that. I just did scheduled brake flush in July, and it is now showing the pop-up, warning me of the scheduled service (oil change) in December. The 'free' four year maintenance that comes with the car new, doesn't transfer to the next owner, but I had BMW 'refresh it' to me as 2nd owner for a $$ fee, so it covers scheduled dealer maintenance to car through the end of the manufacturer's warranty, which is up in March 2020. Once out of warranty, it will likely be going to a (less expensive) independent BMW only service garage near me in Dallas.

As a follow up, the dealer verified the CEL light was illuminated and initially got Fault 21E96F (driving readiness information) and the information could not be established whatever that means. He then got Fault 805516 (AC Charging Unlock) to this they asked if I had any problems charging. In the almost 6 months we have owned the car I had trouble one time removing the charging connector from the car. My JuiceBox 40 Pro had shut down (this unit has since been replaced by JuiceBox) and I have never had problems again with the charging operation or the charger. The tech cleared all codes, the CEL are out and we are moving on. On a side not they noticed the boots over the front struts were ripped so they replaced them another day under warranty.
Once again thanks for your inputs!!