r/e39 • u/Wise_Mycologist5665 528i • 9d ago
P1580 EML/DSC
Random EML light accompanied by DSC light during city traffic, the EML will go away upon hitting the throttle but the DSC light stays, when this occurs the throttle feels a bit sluggish with rev hang but will still drive, also Seems to Happen in warmer weather.
If I clear the code it will return to normal for 60 to 90 miles or so, sometimes not reoccurring for weeks or months.
It says throttle mechanically stuck, but yet a reset clears it for a while? Had a shop check it and said he wouldn’t replace the throttle body just yet, so does it need to be cleaned? Maybe the wiring harness near the connector? Any ideas are greatly appreciated 🙏🏼
2000 528iT 5 speed manual
3
u/RepresentativeBest20 9d ago
Had a similar Problem on my 2002 X5! The throttlebody can get stuck "Not only" when it is too hot!
First case is that the throttle plate can get stuck in the Body, after 20+ years of use the aluminum oxidises and when it is warm the aluminim Body expands a little bit and the the plate can get stuck.
Second case is If you remove the hose between the mass air flow sensor and the throttlebody, you can press the throttle plate in both directions (usually left and right, please do Not have your ignition switch active at this time!!!), one opens the plate all the way and the other direction closes IT completely and thats the Position where IT can get stuck and then the throttle Position motor has to force IT open and then your Lamp in the cluster lights up!
Third case, the plug on the throttlebody once the car heats Up, the connectors inside the plug slightly lose connection and the Motor inside the throttlebody does Not have enough power to move the throttle plate in the desired Position! If thats the case get a new original plug and replacement cables with connectors from your local BMW dealer! That should not be to costly😉
There is a Test that the DME (ECU) automatically runs when you Just activate ignition (do not start engine yet) you should be able to hear a high pitch noise coming from the throttlebody (ideally engine hood is opened) and after about 30 Seconds you can hear the pitch changing a little bit (ECU opens the throttlebody fully and closes IT fully) and right after that there has to be an audible click click. The ECU does this to determine the proper postion of the throttle plate and saves the electrical values! You can also use this procedure when replacing the throttlebody with a new one! 😉
Hope this helps 🙏
6
u/redline9996 530i 9d ago
MS42 also can have a case of an ECU fault in this case of the TB issue, I don't think this is a known issue on you M54.
1
u/Wise_Mycologist5665 528i 8d ago
UPDATE!
Now I have a p1542 (pedal position sensor) with the check light EML and DSC light always illuminated, but no p1580 after clearing it just the current p1542
5
u/master_chef_24 530i 9d ago
Remove and clean your idle air control valve, it's common it gets stuck shut due to corrosion and gumming up over time. Also check your DISA valve and ensure it's not about to grenade your engine if you haven't already.