Engine check light

[spartacus68]

My wife has been running her 2015 REx for about 4 years now. In that time it's had the front suspension dust covers renewed, and the fuel pressure sensor done under warranty. I've serviced it a couple of times including filter changes and oil change.

This week she had to use the hold charge facility as travelled a bit further and needed engine to engage and engine check light is now illuminated. The engine did run. I've checked onboard computer and it says car systems are ok, other than a reminder for brake fluid change which incidentally I did last November.

Of course, the car is now outside warranty, and a quick search reveals it could be everything from fuel injectors to 02 sensor, or possibly nothing at all. If I was wanting to scan the car, what software do I need please? I'm used to car software as run VAG VCDS on an Audi and Volkswagen diesels.

Is it even worth trying to scan? Looked at online video, so injectors aren't that inspective (compared to BMW doing it) and can be accessed. However before I start replacing parts I really need to identify issue.

 

[SwissDI3]

Before you start replacing hardware, I would
- buy the Bimmercode App
- clear all the error codes.
- wait

If the engine light comes on again:
- replace the fuel pump relay (costs around 15.- Bucks and 20min DIY) - this normally accounts for 50% of all problems

 

[TOEd]

https://www.mybmwi3.com/forum/viewtopic.php?t=16679

 

[spartacus68]

Thanks for the replies. Booked in Friday with my local mechanic. Keep you posted.

 

[rtanov]

Autozone will pull the error code for free - at least they used to - haven't been there since we got rid of all our ICE cars 5 years ago The code they pull out might not be very informative but it could be a great google search starter to diagnose the problem. This could be a major or a minor problem - I had my REX engine replaced after a persistent CEL error.

 

[jadnashuanh]

There are generic codes any OBD-II reader can query, and then there are BMW specific codes, where you need a system designed to interpret them. The OBD port has two different data paths in it...not all readers can communicate on both of them. One is unique to BMW, the other is generic to all OBD-II capable devices.

 

[spartacus68]

Update on this and the current saga.

So the car went to my local mechanic who had it for over two weeks waiting for a part - and he changed a Lambda O2 sensor, but problem still persisted. I'm still awaiting that invoice.

So off to main BMW dealer who inform me it's the fuel pump. I've read a number of links regards the fuel pump sensor and I was tempted to try the fix, but given it's at the main dealer, simply removing the car to try the fix it will delay things, and the software scan it's had already would be chargeable again. Already looking at a bill of approximately £650 GBP. Only saving grace is it will come with 2 year BMW parts and labour warranty.

They also found an error related to the A/C - something to do with a sensor that switches of pulling in air to recirculating if air quality is poor. It's not critical, and we have saved £150 GBP. I can attend to this in the future - if ever!

To say I'm angry is an understatement. Car is 2015 with only 40k miles, and the REx does get used, but obviously not enough. I've seen used pumps on Ebay for around £200 GBP, but frankly that's a fool's game if it fails miles from home. It needs to be 100% reliable.

Looking at parts diagrams - it looks like plug and play from what I can see? Not sure if the pump needs to be calibrated to the car. Am I right in thinking it under the bonnet carry box (or as you US guys say the hood)?

Looking at investing in some some software to read codes in the future. I can start a separate thread on that - as hate getting stung by the main dealer.

 

[alohart]

So off to main BMW dealer who inform me it's the fuel pump. I've read a number of links regards the fuel pump sensor and I was tempted to try the fix, but given it's at the main dealer, simply removing the car to try the fix it will delay things, and the software scan it's had already would be chargeable again.

I hope that this problem hasn't been misdiagnosed. Quite a few REx owners with fuel problems have discovered the cause to be an inexpensive relay that is easy to replace. I can't recall reading about bad fuel pumps, but a few are likely to have failed.

 

[spartacus68]

So off to main BMW dealer who inform me it's the fuel pump. I've read a number of links regards the fuel pump sensor and I was tempted to try the fix, but given it's at the main dealer, simply removing the car to try the fix it will delay things, and the software scan it's had already would be chargeable again.

I hope that this problem hasn't been misdiagnosed. Quite a few REx owners with fuel problems have discovered the cause to be an inexpensive relay that is easy to replace. I can't recall reading about bad fuel pumps, but a few are likely to have failed.

I sincerely hope so alohart. :roll:

Just back from the dealer tonight and my wife called me to say the problem still isn't resolved. This was a 2 hour return journey to drive into the city to collect the car. I paid the bill, she jumps in the car then phones me literally 5 minutes from the dealership on the way home to say the fault hasn't been fixed. Pointless going back tonight as their service reception is closed for the evening. I'm incandescent with rage. They didn't even charge the car properly, so my wife got home with 2 miles electric range left with me following behind in another car.

I wouldn't mind - I supplied the car with a covering letter identifying the fuel pump sensor as potential culprit. BMW say the bench-tested the engine and it wouldn't start, so they follow their own literature reference the repair procedure. If it transpires the sensor is at fault - they can reimburse me for the work done. I paid £135 GBP just for the diagnosis. I do get the feeling they don't have a clue about what they are doing, part of the reason I've been servicing my own cars for the last 30 years, as they literally throw parts at a problem to see if it works.

Watch this - I'll do an Halle Berry oscar-winning performance tomorrow morning and go straight to the after-sales manager. Surely they should road-test? I'll keep everyone posted.

Seriously considering ditching this car and trading up for another REx still under warranty.

 

[spartacus68]

Update to the update.

Car back tonight, so NOx sensor fitted by the independent garage has been removed and a genuine BMW part fitted (I was assuming the part fitted already was genuine) and it's still not fixed. Sitting at over £1k in repairs so far. Going to speak to the main dealer tomorrow for a conference call, as the car will now have been to them 3 times and I get the distinct impression they are just throwing parts at it.

When I collected the car after the 75% battery usage I switched to the range extender and it came on fine. Drove the remainder of the way home, and left it with 5 miles on electric before switching it over and then the car threw a 'drive-train error' fault. Long story short - the car used all the electricity and the engine wouldn't engage and the car literally rolled to a halt dead, probably half a mile from home.

By this point I'm about ready to throw in the towel and call the AA (recovery). I switched off the car and restarted and the engine extender engaged but sounded particularly rough. Managed to limp home and put it on charge.

Running out of parts for this car. BMW still refuse to change the fuel pump sensor, and if they suggest injectors - they can think again. Could it be a wiring loom or HT lead?

 

[SwissDI3]

When you mention they refuse to replace the "fuel pump sensor" - I hope you are not referring to the fuel pump relay that sits next to the fuses (under the glove box)?

To change that sucker is step numero uno whenever you have any REX issues.
People have swaped out complete engines to find the relay at fault in the end.

You can change it DIY and the part is approx. 15.- Euro!
https://nemigaparts.com/cat_spares/etk/bmw/I01/MCV/1Z81/61_3564/

How to:
https://www.youtube.com/watch?v=KkF5VvmlZCM

 

[spartacus68]

Latest and hopefully final update. Car back from main dealer. In the end they replaced the fuel pump relay. They said there was pitting on the relay and suspected the pump was faulty and drawing too much current.

I even said to check the relay followingvthe forum's advice as mentioned that their I3 tech has never had to replace one?

Difficult to argue with main dealer, as they have the software and supposed knowledge.

Only saving grace is after £1k GDP the pump, relay and NOx sensor are all covered with 2 year parts and labour warranty should it reoccur.

 

[SwissDI3]

Very smooth move by the dealership

In order to justify the pump replacement (which didn't solve the problem and was probably comletely unecessary) , they diagnose that the "faulty" pump damaged the relais.

What a load of BS

But I guess there is no way to prove that they are making this up as they go along !

Keep my fingers crossed for you that the car is back to normal .

 

[jadnashuanh]

A defective pump might pull more current than it should, but typically, that would blow the fuse before it would pit the relay. An intermittent, though, if that caused the relay to open/close frequently could do that. When in the military, on the relay coil, they always seemed to install a diode across the coil to prevent the relay from chattering when the coil was deenergized. Collapsing the magnetic field in the relay coil generates a (usually small) spike or oscillation that an sometimes mess with other electronics.