DTC B12B9-87: Auxiliary Heater Control Module - Missing message: 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.

Refer to the appropriate system wiring diagrams and check the fuel fired booster heater control module power and ground circuits for open circuit, high resistance. Repair the wiring harness as necessary
Refer to the appropriate system wiring diagrams and check the LIN bus circuit for short circuit to ground, short circuit to power, open circuit, high resistance. Repair the wiring harness as necessary
Using the Jaguar Land Rover approved diagnostic equipment, clear the Diagnostic Trouble Code(s) and retest. If the fault persists, install a new fuel fired booster heater control module as necessary