Mercedes Benz

Technical Service Bulletin # 640311 Date: 110301 A/C - No Or Insufficient Heat When Temp. Set To MAX SI B64 03 11 Heating and Air Conditioning March 2011 Technical Service SUBJECT No or Insufficient Heat when the Temperature Is Set to Maximum MODEL E90, E91, E92, E93 (3 Series) SITUATION There is no or insufficient heat when the temperature is set to maximum. After the vehicle has reached operating temperature, the temperature of the air coming out from all the vents is not hot. CAUSE This could be caused by various issues, such as: ^ Coolant insufficiently filled ^ Clogged heater core or blocked radiator and/or hoses ^ Mixing flaps/stratification flap operating incorrectly ^ Ventilation temperature sensor ^ Footwell temperature sensor faulty ^ Interior temperature sensor faulty ^ Water valve not functioning correctly 2010 BMW 328i Sedan (E90) L6-3.0L (N51)   43 ^ IHKA (Integrated Heating and Air Conditioning, automatic) sending incorrect signal PROCED...