In this article we are going to cover most common engine error codes and most common issues.
So don’t be freaked out with CEL and don’t rush into BMW dealer- its not that complicated to diagnose it yourself.
First you need BMW software (INPA, RHEINGOLD, DIS, GT) or even simple OBD reader can be of great help. Any check engine light can be diagnosed with OBD reader, though you cannot go in details, but in most cases is enough.
So you got error codes, now its time to decode them online so you know what those error codes mean.
Good idea to check fuel trims and O2 sensor adaptations, it will tell you if you have any vacuum leaks, which will make your engine run very inefficiently, shaking etc.
NOTE: IF YOU HAVE 0420, 0430 ERROR CODES WHICH TELL YOU THAT CATALYTIC CONVERTERS ARE NO GOOD ANYMORE, IT MEANS YOUR ENGINE IS BURNING OIL KILLING CATS, SO NEW CATS WILL NOT LAST IF YOU DON’T FIX INITIAL PROBLEM WITH VALVE SEALS!! CATALYTIC CONVERTERS CAN EASILY LAST 300-400K, AND THEIR FAILURE INDICATES INTERNAL ENGINE PROBLEMS…
MOST COMMON AIR LEAKS:
-CCV or crankcase breathers. Cracked old membrane will create air leak, so DME will increase fuel trim, making it running rich
-VACUUM PUMP SEALS AND OIL SWITCH will create vacuum leak as well. They always leak after 5 years or so. Solution is simple- RTV or new seals from BMP DESIGN company, since bmw only sells small oring and they want you to buy 300$ vacuum pump instead.
-old oil cap will also create vacuum leak
-leaking valve cover gaskets will also create air leaks and more importantly leaking spark plug pipes will create misfires due to fouling ignition coils. If you remove a coil and its covered with oil, it means its leaking and VCG (valve cover gaskets) need to be replaced asap.
-old rubber intake boot is very common issue on N62b48 engine or BMW 750i, BMW 750LI
-intake manifold gaskets and injector o-rings also don’t last forever
But be aware that some error codes not necessarily mean you need to replace that or these parts. For example running lean or rich does not mean your O2 sensors or catalytic converters are bad. Always check O2 sensor adaptations, and if they adjust mixture and not stuck, it means youve got something else causing rich or lean mixture and O2 sensors have to adapt the mixture.
Sometimes bad Valvetronic or VVTI sensors don’t throw error codes but make engine run rough., you can always disconnect VVTI sensor and your engine will run using conventional throttle body approach, and if it runs smooth without VVTI, it means VVTI sensor is not working well or not adapted.
POST YOUR COMMENTS BELOW AND I WILL TRY TO HELP, you ca also email me, but since its not my primary job, i can not reply asap.
Logic7repair@gmail.com
ABS, DSC, BRAKE LIGHT CHRISTMAS TREE?? NO PROBLEM!!
So you got very nice Christmas tree on your dashboard?? Well dont worry it happens sooner or later to any BMW. So one of a sudden all lights are on and IDRIVE is going crazy?
Don’t worry it can be fixed I under 200$!!
MOST COMMON CULPRIT IS YOUR ABS, DSC UNIT !!! IT DOES GO BAD VERY OFTEN DUE TO AGE AND HEAT UNDER THE HOOD!! There could be other things (abs sensors, harness issues, etc) causing those lights, but if all lights are on especially angle sensor light is on, it means module is dying, MOST COMMON DSC/ABS MODULE FAILURE SYMPTOM-NO ERRORS WHEN COLD AND AFTER ITS WARMED UP EVERYTHING IS BAD.
There are 2 options about it:
-Repair DSC module with warranty (best cheapest option). Don’t buy used one- it might not last and can also be bad and worst part you have to code it, which is not very simple procedure. Always try to fix it or get new one, WHICH IS SELF CODING AND WILL CODE ITSELF AFTER YOU PUT IT IN.
-Buy new module for 600$, self coding- will code itself after you installed it. Great option, but I think rebuilt one is better since its going to be stronger than OEM.
Replacing is easy: remove the unit, send it for repair or replace it with new one. Located on passenger side, black unit. You need to remove coolant tank to get access to all bolts holding it.
So it wasn’t very bad, isn’t it? Enjoy fully working dsc system, it will also affect transmission shifting, because its reading lots of signals form DSC unit. Bmw dealer will charge you more than 1200$ for it.
Hi. I have 730d which has suddenly decided not to go over 40mph to get there takes alot longer than before it wont go past 4th gear on auto.
Diagnostic fault showing fault with throttle body. No EML
Could this be a problem or transmission?
Thanks in advance
DOES TRANNY HAVE ANY CODES? IF NOT THEN ITS YOUR ENGINE, THOTTLE BODY CAN CAUSE THIS TOO
Hello,
I have installed many versions of INPA on a windows 7 laptop. I have the USB to OBD adapter. I can only see and clear codes, i can see many modules but i cannot access anything regarding the engine which would allow me to use the cylinder run rough display etc( tells me thst the vanos module has not been initialized). I have successfully installed and coded a new DSC unit for example of what i can do with the version i have but what version of INPA do you use and where can i get it? I want a version which will allow full functionality and programming/coding for 2008 750Li
dme not suppported with your inpa version, get ISTA D
Fixed surging/high idle on ’04 745Li with new throttle body. 265 new on web, not the end of the world.
Throttle body doesn’t go bad often on these cars. You had a tb code?