35d: 40mpg, try to pass, engine dies

[torqueisking]

title edit - should be 40MPH
Driving along at about 20%? throttle at ~40MPH, press the throttle to ~70%, engine dies and I coast to the side of the road. First time this has happened.

I try to restart, engine won't fire. Removed the key, try it again and it fires just fine. Drive conservatively for 45minutes with no problems. Tried to recreate the scenario and condition. Engine dies again. Drove home at light throttle with no problems.


I used INPA to read the 28 error codes stored in memory. They are all over the place. I think that’s typically battery related but I had mine fully tested a few months ago it was good as new. I cleared the codes.


Two days later, after about 20 minutes of city driving, the engine dies with ~10% throttle at ~20MPH. The second restart attempt was successful and I was able to slowly drive home.



Another error code dump found reappearing 4 errors codes.


JBBF, Junction Box - Passenger : A6D1 (Auxiliary water pump)
DDE: 4B99 (Injectors, bank 2, activation)
ZBE, idrive touch controller: A2CD (Control unit, undervoltage)
KLIMA, Heater/automatic A/C control: 9C55 (Electric auxiliary heater)


First theories are a shorted injector coil or a shorted Aux. water pump coil (it’s electric). Next step is to disconnect the Aux water pump connector and see if the engine dies while driving.

Working this vehicle can be a real PITA without a repair manual. I have TIS but only up to 2008. Hours of google searching reveals very little. There’s an online TIS but it doesn’t really provide enough information. What are the BMW techs using to repair these vehicles? Any know where I can find a wiring diagram?

[Proflyer]

If you battery is over 4 years old, replace it. Walmart actually sells a replacement that works great. These cars are very temperamental to low voltage issues. Make sure you register the new battery so the ECU knows its now a new one. I was chasing a million electrical gremlins in by 335xi and my wife's 35d X5 and two new batteries fixed them all. You have several codes that all can be due to low voltage.

[boredincl]

Originally Posted by Proflyer

If you battery is over 4 years old, replace it. Walmart actually sells a replacement that works great. These cars are very temperamental to low voltage issues. Make sure you register the new battery so the ECU knows its now a new one. I was chasing a million electrical gremlins in by 335xi and my wife's 35d X5 and two new batteries fixed them all. You have several codes that all can be due to low voltage.

+1

[sgrice]

Also, check for the plastic partitions at the back of the engine bay. They commonly crack/split and leak water which corrodes injectors with the car dying on acceleration just as you describe. If you are unaware of it, this link will be very interesting reading. Some of the codes are the same as yours, and the symptoms seem nearly identical. If your engine partitions are cracked (should take about 2 minutes to check), then injector corrosion is likely the issue.

Hope that helps.

Stephen

[torqueisking]

Split partitions - we have a winner. Will try to chase the stealership to fix it as it is an SIB but looks like that still leaves me with a bad injector. Thanks for the link.

Found a website that lists the SIBs. So many for my vehicle!

2010 BMW X5 Technical Service Bulletins (TSB)


Thought of the battery but my battery cranks like a champ even at -15degC.

[ZetaTre]

Originally Posted by sgrice

Also, check for the plastic partitions at the back of the engine bay. They commonly crack/split and leak water which corrodes injectors with the car dying on acceleration just as you describe. If you are unaware of it, this link will be very interesting reading. Some of the codes are the same as yours, and the symptoms seem nearly identical. If your engine partitions are cracked (should take about 2 minutes to check), then injector corrosion is likely the issue.

Hope that helps.

Stephen

^^^^^^ This ^^^^^^^

Injector 5 shorted, replace injector, code injector, remove and trash the foam over engine (that the only thing it's good for is collecting water), fix partition (the new center piece is now made of hard plastinc instead of some sort of cardboard).

[blue dragon]

Injector number 5....
It strikes again

[G550Mech]

EXACT scenario for me just 3 weeks ago...dealer replace #2 injector under CPO...next day, highway speed, same result. Took back to dealer, replaced ALL injectors, been working great ever since!

[torqueisking]

Finally had a chance to dig into this starting with the partition replacement. BMW unfortunately won't replace any SIB documented issues.

Looks like a corrosion problem, no? That bolt from the rear acoustic cover looks like it came off a 20yr/old vehicle. It was a 5mm socket cap screw.





You guys guessed it, unlucky #5. Obvious from the corrosion!


Design of the partitions are much improved especially the center. It can't leak between the joints due to the co-injected rubber flaps/edges. The material has also changed as you can see from the photo below. They've added a blowing/foaming agent to the plastic but didn't change the thickness. I'm embarrassed to admit that I cracked the right side partition during the install. It as brittle as a potato chip and about as thick as one where it cracked. Added some epoxy and now good as new. Took the SOs watering can and testing the drainage. No leaks in the joints but the left side drains dangerously close to the DDE case.

My outdoor parking situation may have accelerated the corrosion because my driveway in on a 5-7deg incline and I park front down so the rain/melting snow drained forward over the broken partitions. Now I will only park backwards so it only drains out the sides.




I disconnected the electrical connecter on injector #5, sprayed the entire area with WD40 and used compressed air to clear the excess.

After assembling it all, I took it out for about 20 minutes. Once it reached operating temp,I stopped on it a couple times then drove home. It ran perfectly. We'll see how long that lasts. I'm just very relieved that the DDE isn't toast. That's also in an SIB.

[ZetaTre]

Keep the foam off. And my recommendation is for everyone to remove it it serves absolutely no purpose other than trapping water and corroding stuff.

Good job on fixing it with WD-40!!!!