Mercedes V Klasse Fuel Consumption and Starting Issues Resolved

A defective throttle valve can certainly cause those symptoms. The increased fuel consumption is because the engine management system is trying to compensate for the incorrect throttle position reading. Poor starting can also result from the incorrect air-fuel mixture caused by the faulty throttle position data. I'd check the throttle body for excessive carbon buildup, which can interfere with the proper valve operation. Have you checked for any error codes using an OBDII scanner?

I performed an OBDII scan, and the code indicated a throttle position sensor malfunction. Should I focus on cleaning the throttle body and inspecting the air intake system before replacing the accelerator pedal module? Or should I address the sensor issue directly, and if so, is replacing the entire throttle body assembly advisable?

The error code points towards the throttle position sensor. While cleaning the throttle body is generally good practice, the code suggests a more specific fault. Given the vehicle's age, the sensor itself may be failing. Replacing the entire throttle body assembly, while more expensive upfront, ensures you're getting a new sensor and butterfly valve, eliminating potential wear. Before that, confirm the wiring to the throttle body is intact and the connector is clean. A poor connection can mimic a faulty sensor. If the wiring checks out, replacing the entire throttle body would be the next step. A workshop should be able to confirm.

I inspected the wiring, which looked fine. I had the throttle body assembly replaced at a workshop. It cost 205€. The symptoms are resolved, and the vehicle now has improved fuel efficiency and starts without issue. Thanks for the expert advice.