Why doesn't the speed increase when stepping on the accelerator in a Mercedes-Benz?
2 Answers
Mercedes-Benz accelerator pedal not increasing speed is mainly caused by issues such as a dirty or voltage-imbalanced throttle position sensor, faulty accelerator pedal, clogged fuel system, or ignition system failure. Here is additional information: Vehicle throttle malfunction: It can be determined that there is a problem with the car's accelerator pedal because when pressing the accelerator, the cable drives the throttle valve (i.e., the throttle). The throttle valve is equipped with a position sensor, and the control unit uses the signal from the throttle position sensor to determine the throttle opening and then calculates the corresponding signal voltage. Calculating fuel injection: Finally, based on this signal voltage, the vehicle's fuel injection volume is calculated. Therefore, if the throttle position sensor is too dirty or has voltage imbalance, it can lead to electronic throttle failure, resulting in the situation where the speed doesn't increase even when the accelerator is fully pressed. Checking the intake system: After ruling out faults in the electronic throttle, attention should be turned to the engine's intake, fuel, and ignition systems. A fault or abnormality in any component of these systems could cause the engine speed not to increase when the accelerator is fully pressed.
I've been driving Mercedes for over ten years and have encountered quite a few situations where pressing the accelerator doesn't translate to speed. The most common issue is transmission problems, especially with the older 7-speed models—sticking valve bodies or insufficient oil pressure can lead to poor power delivery. Last time this happened to me, I found the mass airflow sensor was clogged with dust, preventing the engine from getting enough air and thus lacking power. Additionally, the ECO mode in Mercedes makes the throttle response particularly sluggish when activated, and accidentally pressing the paddle shifters can lock it in a low gear. You also have to watch out for fuel quality; some small gas stations in China sell 95-octane gasoline with too much water content, which can clog the fuel filter and prevent the RPM from rising even when the accelerator is floored. If these issues aren't addressed, driving like this long-term can cause significant damage to the engine and turbocharger.
