Mercedes ML hybrid tailgate sensor fault

Your described predicament with the Mercedes ML tailgate electrical sensor is a commonly reported issue. The error stored in the memory, coupled with the symptom of incomplete tailgate opening, strongly suggests a malfunction within the sensor circuit. Before proceeding with a costly repair, several diagnostic steps can be undertaken. Firstly, a meticulous visual inspection of the sensor wiring harness is paramount. Examine the harness for any signs of physical damage, such as fraying, cracking, or exposure of conductors. Subsequently, scrutinize the plug connection to the sensor, ensuring it is securely seated and free from corrosion. The integrity of the ground connection for the tailgate circuit should also be verified, as a faulty ground can induce spurious sensor readings. Furthermore, it is advisable to consult the vehicle's wiring diagram to ascertain the precise location of the sensor and its associated components. Do you have access to the wiring diagram, or a multimeter to check the wiring?

Thanks for the detailed reply I don't have a wiring diagram handy Where exactly is the sensor located, and would I need any special tools to access it Also, you mentioned a multimeter, what readings should I be looking for on the sensor wiring

The tailgate hall sensor is typically integrated within the tailgate latch mechanism itself, or in close proximity thereof. Accessing the sensor may necessitate the removal of interior trim panels from the tailgate. Proceed with caution during trim removal to preclude the possibility of inflicting damage. The utilization of specialized trim removal tools is recommended. Regarding the multimeter readings, consult the vehicle-specific repair manual or technical documentation for the precise voltage or resistance values that correspond to the sensor's operational states. However, without the wiring diagram, it's difficult to give precise instructions. In this case, it is recommended that you seek the services of a qualified automotive technician to perform a comprehensive diagnostic evaluation and sensor calibration. The eventual repair cost should be around 95€.

Thanks for the advice. I took it to a local shop, and it turned out to be a broken wire in the harness, just like you suspected. They repaired the sensor wiring, cleared the code, and now the tailgate opens fine. The sensor calibration was ok. Cost me 95€, so all good!