MERCEDES-BENZ · 2022-12-11
Complaint Various customer concerns of Climate Control system operating inadequately. Cause Stepper motor linkage in the heater case may cause a mechanical fault during actuation during unfavorable environmental conditions. NOTE: If the vehicle is equipped with H13 (rear additional heat exchanger), There is an additional stepper motor in the rear heater case under the vehicle. This stepper motor can influence the normalization process. May include fault code: B1A9C07 the output for control valve "Left water valve" has a malfunction. There is a mechanical fault. The component is called N29/12 (rear additional heat exchanger ) . Remedy: See instructions