HELP...understand what these codes mean!
 

Had my local dealer pull some codes off my 2001 E430 2.8 ME unit:

P20D4 - This load limit is active (P1999)
P203B - Fault of function monitor in electronic accelerator (P0221)
P2004 - B2/5 (Hot film MAF sensor); shot circuit to battery or reference voltage (P0103)

Can any of you tech guru enlighten me with what this all means? Any parts need to be replaced?


Any info is greatly appreciated :)

Regards
Richard

It's funny you post these codes, I have had 2 cars in the last couple months with this same series of faults. One was an '04 ML350 that was repaired with an engine harness, I never did find a fault in the harness during testing, but replacing it took care of the problem. The other is an '05 C320 that I'm working on as we speak. It appears that the throttle acuator is faulty on this car as it is testing bad intermitt. I will be replacing it tomorrow when that part shows up and will let you know my findings.

The DTC relation is due to the fact that the MAF sensor and the throttle actuator share the same 5V reference signal internal of the ME 2.8 ecu, along with the purge valve, MAP sensor, fuel tank pressure sensor, etc... So if there is a short on that 5v reference signal it may trip codes for any of those components as they will send a failed signal without a correct 5v signal.

Bottom line, this isn't going to be an easy DIY project. I have the luxury of all the factory manuals and SDS machine, as well as 12 years experience on MB and it's giving me headaches.

benzaddict SG,

Thanks very much for your technical reply, my car is still at the dealership and awaiting results. They did say the MAF was replaced.

Pls let me know your findings on the throttle acuator. :)

Regards
Richard