Mercedes ML diesel engine power loss

I had a similar problem with my Mercedes ML same model I got the reduced power and the check engine light Did the auto scanner give you a specific fault code Knowing that would help

Yes the auto scanner did provide a fault code but I did not record it at the time Would the specific fault code significantly alter the potential diagnosis or recommended course of action

Yes knowing the fault code makes a big difference For me it turned out the chip tuning messed things up like you suspect I'd recommend taking it to a workshop with experience in Mercedes They'll be able to read the code and tell you for sure

I appreciate your advice I took the vehicle to a qualified workshop and they confirmed your suspicion The fault code indicated a problem stemming from the aftermarket chip tuning The repair which involved reconfiguring the engine management system cost 180€ The vehicle now operates as expected Thank you for sharing your experience it proved to be invaluable