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Home >> Land Rover >> 2021 >> Discovery S >> Repair and Diagnosis (Single Page) >> Quick Lookups >> DTC Index >> Diagnostic Trouble Code Index DTC: HVAC Control Module (HVAC) -- Discovery/L462 >> General Information >> Description And Operation >> Diagnostic Trouble Code Index - DTC: HVAC Control Module (HVAC) (G2016105) >> DTC B12B9-4B: Auxiliary Heater Control Module - Over temperature >> Action
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DTC B12B9-4B: Auxiliary Heater Control Module - Over temperature: Action

NOTE:
  • The fuel fired booster heater contains many serviceable components. It should not be necessary to install a new fuel fired booster heater to rectify this fault.
  • To check the operation of the fuel fired booster heater, perform routine - Auxiliary Heater (AHCM) Activation Test (0x900A). Repeat the routine if excessive smoke is emitted from the fuel fired booster heater exhaust.
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