2010 X5 35d - won't start after injector replacement

[torqueisking]

Originally Posted by ninja_zx11

I was lying that -ve is shared between all injectors of bank 2.After looking at wiring diagram it appears that DDE supplies each injector +ve and -ve separately.So its puzzling why DDE is throwing complete bank 2 activation code unless all 3 injectors are bad

Thanks for posting this! Once again I'm stumped. If the DDE supplies both +ve and -ve, it should be able to report a single injector short and there would be no reason to report "bank" error codes.

I was confident of the bad injector #5 diagnosis when removing the #5 injector connector after it wouldn't fire. And then it started. So if any other injector/wire was shorted, that action shouldn't have started the engine?

[ninja_zx11]

Originally Posted by torqueisking

Thanks for posting this! Once again I'm stumped. If the DDE supplies both +ve and -ve, it should be able to report a single injector short and there would be no reason to report "bank" error codes.

I was confident of the bad injector #5 diagnosis when removing the #5 injector connector after it wouldn't fire. And then it started. So if any other injector/wire was shorted, that action shouldn't have started the engine?

Yes you are right...

[ingenieur]

This is a bit odd perhaps corrosion in the harness. Just curious - does it still set the fault? - they are not monitored individually as each bank ground is common internally in the DDE - no individual injector faults are listed in the table.

Edit: The table does list possible injector faults for each power and ground control - but they may only set in the case of a circuit interruption as when you disconnected #5. Did this set another fault?

[ninja_zx11]

[QUOTE=ingenieur;1068955 - no individual injector faults are listed in the table.[/QUOTE]

Yes it is odd.But in the SIB that I posted in my earlier post,it does shows individual injector activation error codes.I am just guessing that even -ve must be monitored.Saying because when I was having problem with urea injector,I removed the plug to the injector and after that DDE was throwing both +'ve and -ve errors.

[blue dragon]

4b99 is activation for the entire bank, mine ended up throwing a different code for the specific injector as well (445C for injector number 5).

I'd check the harness going to that bank of injectors.

[G550Mech]

Just to reiterate on your original post about the vehicle shutting off while driving. Exact same scenario for me, drive, turned a corner speeding up to flow of traffic, car shut off. Dealer says fault showing "Bank 2 Injector", replaced #2 injector, same results next day, shut off on me. Took it back, same fault code, replaced ALL injectors, no problems since.

[torqueisking]

Thanks to all for the brainstorming!

Some conflicting evidence here with the previous codes but engine running after removing #5 injector connector appears to confirm the problem injector was correctly identified and the wiring harness is not at fault.

Once the #5 injector was replaced, the 4B99 code did not reappear. I didn't check the codes between the time that I removed the #5 injector connector and after it was all back together with the new injector.

G550MECH: Bank 2 refers to the 4,5 and 6th injectors. Sound like they initially replaced the wrong injector. What a waste to replace all of them. Dumpster diving at the stealership could be very profitable.

Since Friday, it's been way too cold (-20degC, -4degF) to continue troubleshooting. The vehicle is outside on my driveway. The cold blast should be ending on Tuesday.

[ninja_zx11]

Torqueisking great job in diy troubleshooting!!Hope you will find the solution soon.

Did you replace no.5 with new one or used?

[ninja_zx11]

One more thing you can do is to remove no.5 connector and try to start and then scan if you see open circuit error.Then remove any connector from bank 1 and compare the codes from bank1 to bank2.

[G550Mech]

Not debating any of the information, I'm just letting you know what the dealership did under CPO Warranty to fix my problem which WAS similar to the one posted, and I haven't had a problem since. Mine runs just fine, but I also haven't been dorking around with it trying to fix the problem. Cheers!