DTC B1D26-12: Combustion Air Blower - Circuit short to battery: Action

NOTE: The fuel fired booster heater assembly contains many serviceable components. It should NOT be necessary to replace the entire fuel fired booster heater unit to rectify this fault

Check the fuel fired booster heater air intake and the fuel fired booster heater blower for signs of restriction from sediment or debris. Remove any foreign matter from the air intake and blower assembly. Clear DTC and retest
If fault persists, Refer to the appropriate system wiring diagrams and check the fuel fired booster heater blower circuit for short circuit to power. Repair the circuit or install a new blower located within the fuel fired booster heater as necessary. Using JLR approved diagnostic equipment, clear the DTCs and perform routine - Auxiliary Heater (AHCM) Activation Test (0x900A). This will operate the fuel fired booster heater for 15 minutes. Note that the routine should be started only when the engine is cool. The routine should be performed with the engine running and with the climate controls set to maximum heat and maximum fan. Repeat the routine again if smoke continues to be visible from the fuel fired booster heater exhaust pipe or from the area surrounding the fuel fired booster heater
If the fuel fired booster heater does not operate correctly following replacement of the blower located within the fuel fired booster heater, replace the fuel fired booster heater combustion tube and evaporator assembly, clear the DTCs and perform routine - Auxiliary Heater (AHCM) Activation Test (0x900A)