HELP!!! "Service Engine Soon" light, following jump in RPM's

tommyjb04

Member
i started my car as normal today, i usually like to start it and allow it to run about 5 minutes before i drive. i jumped in, went to the gym (turned the car off), went to the building to find they were closed, came back to the car, started it and the car idled wildly, jumping up in rpms and back down quickly almost like "coughing" and the service engine light came on, i quickly turned the car back off and checked my floor mat b/c i thought it was possibly pressing the gas pedal, restarted it and it did the same thing again, i quickly turned it back off and checked my gas cap, under the hood for anything obvious, and even my tail pipe, nothing unusual from what i could see. So i waited a good 5 minutes, restarted it and it started fine but the service engine light remained on. I visited pep boys and they pulled the code P16B9 but could not tell me what it meant, i visited 4 others shops and they all refused to even check it and referred me to the dealership. After the last shop I started the car and the service engine light turned off. I have recently (in the past month) experienced a "studder" at cold starts, I turn the key and it repeatedly tries to start but does not, i turn it off, take the key out, go right back in and it starts up immediately. I have also recently experienced a rough idle, where i'm sitting at a traffic signal and it seems as if the rpms drop "to low" and i feel a rough vibration, i press the gas pedal slightly to boost the rpms and it idles fine. I (personally) changed the oil, installed new spark plugs, and a new air filter w/in the last 2 months. This is my first bmw, although my wife now has an x3, this is the first time my service engine light has come on, my z4 is a 2003, 2.5 automatic with only 38k, i am still pretty new to the forums but have searched to find various remedies such as the having the dealership update the software in the cars computer, the DINA, the MAF, this a result in a forum the code P16B9 Eigendiagnose Motorsteuergerät - Überwachung Drehmomentverlust - Kabelbaum, Motorsteuergerät, but its in German, any help at all would be greatly appreciated guys, also I am in Hampton, Va., so if anyone knows any repair guys or shops in the area plz lemme know, i tried contacting "shipkiller" since he's right down the rode, but i cant figure out how to email him directly, I hope he sees this post, thanx Thomas
 
Google translator says : Self-diagnostic engine control unit - monitoring loss of torque - harness, engine control module

:thumbsup:

Of course i cannot tell you the problem, but someone on here probably can
 
Not sure what the cause is, but it may be clogged/dirty fuel injectors not delivering enough fuel. Not sure about the 5min idle warm up time; typically some easy driving is better to heat up the oil rather then just letting the car idle.

The translation for the German parts are:
P16B9 Eigendiagnose Motorsteuergerät - Überwachung Drehmomentverlust - Kabelbaum, Motorsteuergerät,
Means Code: P16B9
Eigendiagnose = Self Diagnostic
Motorsteuergerät = Motor control unit
Überwachung = Monitoring
Drehmomentverlust = Angular Momentum Loss
Kabelbaum = Cable cluster or direly translated cable-tree

So:
P16B9 = Self-Diagnostic Motor Control Unit - Monitoring of Angular Momentum Loss - Cable cluster, Motor control unit

Best of luck!
Keep us posted
 
:rofl:

We posted at almost the same time systemlord - I think google said the same as you, just less literal...
 
We posted at almost the same time systemlord - I think google said the same as you, just less literal...
Yes i started my reply and then i saw you post popup ;] - Had to make sure my spelling was ok.

So maybe some fuel injector cleaner???
Before throwing money at it I would start with that and also get a new batch of high grade gasoline.
May that will solve the problem; but hopefully someone else here has some more insight into the problem.
 
i'm open to trying just about anything, this is my daily driver and i need my z4!!! i will try some fuel injector cleaner and repost, but my gut is telling me this problem is a bit more complex...
 
tommyjb04, could be the coils. Had mine sputter about and crippled it along to the BMW Service center. This was warranty work done a few years back. Doesn't sound like the same symptoms.
There is a place in Yorktown (RT 17) called Auto Haus that specializes in German motor cars. Also a place in Williamsburg called European Cars which I used before.
 
BSVA said:
tommyjb04, could be the coils. Had mine sputter about and crippled it along to the BMW Service center. This was warranty work done a few years back. Doesn't sound like the same symptoms.
There is a place in Yorktown (RT 17) called Auto Haus that specializes in German motor cars. Also a place in Williamsburg called European Cars which I used before.

Thanx for the references, ive recently moved up to va. and would like to avoid dealership costs, and if anyone has had a related problem maybe even repair it myself..
 
Yeah dealership costs can be......costly.
Shipkiller would be the one to talk to.
Let us know how it turns out.
 
If the EML comes on in response to a problem, it will stay on until the car has been restarted three times without that problem being detected, but the code is stored. I had this problem with my ///M a couple of years ago, and it never happened again - I've forgetten the code now but it pertained to the MAF. I know it's a completely different engine, but hopefully that will be the end of it for you too. I would reset the throttle, and just drive it normally for a while and see if it happens again.
 
BMWZ4MC said:
If the EML comes on in response to a problem, it will stay on until the car has been restarted three times without that problem being detected, but the code is stored. I had this problem with my ///M a couple of years ago, and it never happened again - I've forgetten the code now but it pertained to the MAF. I know it's a completely different engine, but hopefully that will be the end of it for you too. I would reset the throttle, and just drive it normally for a while and see if it happens again.

that sounds exactly right!! once i restarted it the third time it ran fine, this happened yesterday and today, but after the third time (again) today it would not start. Its idling wildly, the service engine soon light, the eml light, the BRAKE light, and the light with an arrow going around the top of a triangle, all remain on. I have a vid i will post as soon as i am off wrk and manage to get it home, right now its stuck in the parking lot.... :cry:
How do i reset the throttle??
 
i took it to a local shop for a diagnostic and they pulled the code:

MS45-DME FAULT CODE 28C
(Torque Function Control)

Shop recommended removing, cleaning, and inspecting the cold start valve, ($315) and possibly replacing the DME (no quote given).
 
Someone... Anyone able to help???
I've got an appointment for a diagnostic on Friday at the dealership... If anyone has any ideas plz help, I really dont want to be ran over...
 
well the dealership says its my dme, they charged me 70$ for the diagnostic, then another $120 to flash it with the lastest updated firmware, still idles slightly rough, but nothing as wild as before, pray for me...
 
If i remember the manual correctly (engrossed when bought first), it says not to warm the engine at a standstill, but to drive straightaway...?
 
Hey dude, have the same problem and the same error code. Do you have any news from your end order to get it sorted out?
 
Hi

I've exactly the same problem on my 2003 2.5 Z4. 99000km

I have noticed that i have the problem only when i stop after a short trip, when the engine is not very hot. No problem when cold in the morning or hot after a more than 30 minutes trip.
I have 28AC nominal torque error. P16B9 control module self test, Torque Loss Monitoring.

The rought idle continues if I start again and again. The only solution that i found is to ... wait about 10 minutes, and the engine starts again. The only light remaining on is the engine light. After 1 or 2 days, the light switch off but the error stays in the DME.

Here is the video of the problem on my car.
https://www.youtube.com/watch?v=fhHqOzprErY

thanks !!
 
i'll share my experiences with this same fault in my 2002 Z4 2.5i

i've had the same start problems for months (starting in oktober, gotten worse in december) when the weather turned colder this winter, and decided not to change my DME/ECU but to give my ECU an software update through the dealer. faultcode in my situation 28AC nomional torque
i updated the DME at the end of january this year (2017) and the problem never occured again.

i'll guess that this problem is gonna be more common in the future, as the car's getting older and one or more "bits" inside the DME tend to fall over, so for future reference: try updating your DME first before spending lots of money on a new DME.
 
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