Mercedes R Klasse Diesel Throttle Valve Issue

A defective throttle valve on your Mercedes R Klasse could certainly explain the symptoms you're experiencing The throttle valve regulates the amount of air entering the engine If it's not functioning correctly, it can lead to poor combustion, hence the reduced fuel efficiency and difficulty starting The accelerator pedal module directly influences the throttle valve's position A faulty module might send incorrect signals, causing the valve to open or close improperly Have you checked the wiring and connections to the throttle body and the accelerator pedal module A loose or corroded connection can sometimes mimic a faulty component Also, what specific error codes are you receiving That information can help narrow down the problem

Right, thanks for the detailed reply I haven't checked the wiring yet, but I will The codes I'm getting are P2006 and P2007 Does that help at all

Yes, those codes typically indicate an issue with the intake manifold runner control valve, which is closely linked to the throttle body's operation While a faulty accelerator pedal module could indirectly contribute, these codes strongly suggest the problem lies within the intake manifold flap system itself or the control valve that actuates it Given the complexity of the system and the potential for misdiagnosis, I'd strongly recommend taking your Mercedes to a qualified mechanic They'll be able to perform proper diagnostics and pinpoint the exact cause of the problem before you start replacing parts

Appreciate the advice Took it to a workshop as suggested Turns out the throttle body control valve was indeed faulty New part and labor came to 205€ Fuel efficiency is back to normal and starts like a charm now