[Ku7114]

Hello folks! Looking to see if anyone had came across a issue im facing on my e92 n54.. so,about a month or 2 ago my 335i started having terrible idle misfires, rpms would drop to almost stalling then surge back up, the vehicle drives good once it gets rolling and also at highway.. the issue is only at idle.. I replaced all ignition coils and also replaced and coded 3 injectors that were leaking, 2 step colder spark plugs as well.. hpfp and lpfp pressures all check out aswell. I took to a shop to get valves cleaned but after picking it up, the car had a engine malfunction light and boost cut off (crankshaft sensor fault), i took the vehicle back and they informed me that the car no longer started even after replacing the sensor… i took it back after weeks of the shop checking wires, grounds and fuses. And i am left with CAS faults, i sent out the Dme,cas & key to get check and they work perfectly fine on the 335i they tested it on…so im wondering if anyone has any knowledge on what it could be?(wipers,ac,speakers,instrument cluster all work fine) and yes the car cranks all day long but wont start. Appreciate yall in advance

[maarzz]

I have a similar situation. Recently, I replaced my alternator and the car ran fine for 5-10 mins when I did a test run to see if the new alternator was working fine. All seemed fine, but I did not drive it, just idled. After a few weeks, I cranked it, it started right up, but then started idling very rough and stalled! After that it just kept cranking and did not come on. I thought it could be the battery, so put it on a charger, but even after full charging, same thing, cranks but doesn’t come on. I thought the DME MOSFET failed so I researched how to test etc and my options. But today, after 2 days, from the last time I charged the battery, when I went to open the car so I could get the DME out, I found the car was completely dead! The battery is fully drained! So now I am completely confused what’s going on, because up until now, the car had been sitting for weeks and the battery was fine. I hope I can get some clues from responses to your issue.
Here is the list of codes I got:
29DB - DME: Smooth running, segment timing.
2AB4 - DME: DME, internal fault: RAM checksum.
2ACB - DME: DME master relay, activation.
2DED - DME: Power management, closed-circuit current violation.
2F0C - Intake air temperature sensor.
30BA - DME: Injectors 1, 2, 3 or DME, internal fault.
30BB - DME: Injectors 4, 5, 6 or DME, internal fault.
CDA8 - Message (status, KOMBI, 0x1B4 ) incorrect, receiver DME, transmitter KOMBI

[Ku7114]

I’d check to see if the battery is good internally, take to auto store and have them test it, if its good and the alt is good too, id replace the ibs sensor because if a dead battery is picked up by it then itll kill the car too, i had a bad ibs sensor and it would start off with not light up the halo rings when unlocked, then after a day or 2 i would notice severe battery discharge messages on dash and then eventually the car wipers went on their own and car died on me in the highway!!!
If you do replace the sensor it has to be coded with the new battery to let the car know that its new!

[maarzz]

Thanks man! I’ll do that, although my battery is fairly new, about a year old and has a 3 year warranty! So maybe I’ll just get it replaced under warranty if needed. Although, I must confess, I have not gotten any battery related warnings or codes!

[suspect]

Originally Posted by Ku7114

Hello folks! Looking to see if anyone had came across a issue im facing on my e92 n54.. so,about a month or 2 ago my 335i started having terrible idle misfires, rpms would drop to almost stalling then surge back up, the vehicle drives good once it gets rolling and also at highway.. the issue is only at idle.. I replaced all ignition coils and also replaced and coded 3 injectors that were leaking, 2 step colder spark plugs as well.. hpfp and lpfp pressures all check out aswell. I took to a shop to get valves cleaned but after picking it up, the car had a engine malfunction light and boost cut off (crankshaft sensor fault), i took the vehicle back and they informed me that the car no longer started even after replacing the sensor… i took it back after weeks of the shop checking wires, grounds and fuses. And i am left with CAS faults, i sent out the Dme,cas & key to get check and they work perfectly fine on the 335i they tested it on…so im wondering if anyone has any knowledge on what it could be?(wipers,ac,speakers,instrument cluster all work fine) and yes the car cranks all day long but wont start. Appreciate yall in advance

Did you fix this?

[Ku7114]

Did not fix yet, still ongoing process…

[maarzz]

Originally Posted by Ku7114

I’d check to see if the battery is good internally, take to auto store and have them test it, if its good and the alt is good too, id replace the ibs sensor because if a dead battery is picked up by it then itll kill the car too, i had a bad ibs sensor and it would start off with not light up the halo rings when unlocked, then after a day or 2 i would notice severe battery discharge messages on dash and then eventually the car wipers went on their own and car died on me in the highway!!!
If you do replace the sensor it has to be coded with the new battery to let the car know that its new!

The battery was bad, so I got a new one. However, the car is still not back to life. All the original codes have not reappeared now after clearing, and the car now cranks and starts right up but idles very rough. It has the reduced power check engine light on and a while bunch of Throttle related codes. The throttle is completely unresponsive! I am slowly trying to figure out how to zero in on the issue...but thought would check in here to updated you that you were spot on about the battery!

Also, to the OP, any word on how your quest goes?**

by the way... the codes I am getting now consistently are:
2ACB - DME: DME master relay, activation.
2CF6 - DME: Throttle-valve potentiometer 1, plausibility to air mass.
2CFA - DME: Throttle-valve potentiometer 2.
2CFB - DME: Throttle-valve adaptation value.
2D09 - DME: THROTTLE.
2D1D - DME: Accelerator-pedal module, pedal-position sensor 1, voltage supply.

[taylorchuck]

I just had a problem with a crank no start issue. My problem ended up being a hose that had separated from the fitting in the gas tank. Apparently its not as rare as I thought it was. If you can run live data, check your fuel pressure from the LPFP, then check your rail pressure so you know youre getting the proper fuel you need for it to idle smoothly to the injectors.

[SlowE92]

Originally Posted by Ku7114

Hello folks! Looking to see if anyone had came across a issue im facing on my e92 n54.. so,about a month or 2 ago my 335i started having terrible idle misfires, rpms would drop to almost stalling then surge back up, the vehicle drives good once it gets rolling and also at highway.. the issue is only at idle.. I replaced all ignition coils and also replaced and coded 3 injectors that were leaking, 2 step colder spark plugs as well.. hpfp and lpfp pressures all check out aswell. I took to a shop to get valves cleaned but after picking it up, the car had a engine malfunction light and boost cut off (crankshaft sensor fault), i took the vehicle back and they informed me that the car no longer started even after replacing the sensor… i took it back after weeks of the shop checking wires, grounds and fuses. And i am left with CAS faults, i sent out the Dme,cas & key to get check and they work perfectly fine on the 335i they tested it on…so im wondering if anyone has any knowledge on what it could be?(wipers,ac,speakers,instrument cluster all work fine) and yes the car cranks all day long but wont start. Appreciate yall in advance

Whats the battery voltage before and as your cranking the car?