Diagnostic Trouble Code (DTC) Index DTC: Auxiliary Heater Control Module (AHCM)

NOTE: If a control module or component is suspect and the vehicle remains under manufacturer warranty, refer to the Warranty Policy and Procedures information , or determine if any prior approval program is in operation, before the replacement of a component.

NOTE: Generic scan tools may not read the codes listed, or may read only 5-digit codes. Match the 5 digits from the scan tool to the first 5 digits of the 7-digit code listed to identify the fault (the last 2 digits give extra information read by the manufacturer-approved diagnostic system).

NOTE: When performing voltage or resistance tests, always use a digital multimeter (DMM) accurate to three decimal places, and with an up-to-date calibration certificate. When testing resistance always take the resistance of the DMM leads into account.

NOTE: Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.

NOTE: Inspect connectors for signs of water ingress, and pins for damage and/or corrosion.

NOTE: If DTCs are recorded and, after performing the pinpoint tests, a fault is not present, an intermittent concern may be the cause. Always check for loose connections and corroded terminals.

Description And Operation

For a detailed description of the fuel fired booster heater contol system, refer to the relevant Description and Operation.

NOTE: Where an 'on demand self-test' is referred to, this can be accessed via the 'DTC Monitor' tab on the manufacturers approved diagnostic system.

DTC	Description	Possible Causes	Action
B1D22-11	Coolant Temperature Sensor - circuit short to ground	Fuel fired booster heater coolant temperature sensor internal fault	Check and install a new fuel fired booster heater coolant temperature sensor Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D22-15	Coolant Temperature Sensor - circuit short to battery or open	Fuel fired booster heater coolant temperature sensor internal fault	Check and install a new fuel fired booster heater coolant temperature sensor Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D23-13	Overheat Sensor - circuit open	Fuel fired booster heater coolant temperature sensor internal fault	Check and install a new fuel fired booster heater coolant temperature sensor Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D24-11	Glow Plug - circuit short to ground	Fuel fired booster heater glow plug internal fault	Carry out circuit checks, inspect the glow plug cables and connector. Repair the circuit or check and install a new fuel fired booster heater glow plug as required Refer to Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D24-15	Glow Plug - circuit short to battery or open	Fuel fired booster heater glow plug internal fault	Carry out circuit checks, inspect the glow plug cables and connector. Repair the circuit or check and install a new fuel fired booster heater glow plug as required R Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D25-11	Heater Fuel Pump - circuit short to ground	Heater fuel pump circuit short to ground Heater fuel pump failure	Refer to the electrical circuit diagrams and check the fuel fired booster heater fuel pump and circuit for short to ground Repair the circuit or check and install a new fuel fired booster heater fuel pump as required Fuel Fired Booster Heater Fuel PumpRefer Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D25-15	Heater Fuel Pump - circuit short to battery or open	Heater fuel pump circuit short to power, open circuit Heater fuel pump failure	Refer to the electrical circuit diagrams and check the fuel fired booster heater fuel pump and circuit for short to power, open circuit Repair the circuit or check and install a new fuel fired booster heater fuel pump as required Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D26-11	Combustion Air Blower - circuit short to ground	Fuel fired booster heater module failure	Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) If the diagnostic trouble code reoccurs check and install a new fuel fired booster heater module as required Fuel Fired Booster HeaterRefer to Refer to the warranty policy and procedures information, or determine if any prior approval program is in operation, prior to the installation of a new module/component
B1D26-15	Combustion Air Blower - circuit short to battery or open	Fuel fired booster heater module failure	Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) If the diagnostic trouble code reoccurs check and install a new fuel fired booster heater module as required Refer to the warranty policy and procedures information, or determine if any prior approval program is in operation, prior to the installation of a new module/component
B1D26-92	Combustion Air Blower - performance or incorrect operation	Fuel fired booster heater module failure	Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for reoccurrence of the diagnostic trouble code If the diagnostic trouble code reoccurs check and install a new fuel fired booster heater module as required Refer to the warranty policy and procedures information, or determine if any prior approval program is in operation, prior to the installation of a new module/component
B1D26-93	Combustion Air Blower - no operation	Fuel fired booster heater module failure	Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for reoccurrence of the diagnostic trouble code If the diagnostic trouble code reoccurs check and install a new fuel fired booster heater module as required Refer to the warranty policy and procedures information, or determine if any prior approval program is in operation, prior to the installation of a new module/component
B1D27-11	Heater Coolant Pump - circuit short to ground	Heater coolant pump circuit short to ground Heater coolant pump failure	Refer to the electrical circuit diagrams and check the fuel fired booster heater water pump and circuit for short to ground Repair the circuit or check and install a new fuel fired booster heater water pump as required Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D27-15	Heater Coolant Pump - circuit short to battery or open	Heater coolant pump circuit short to power, open circuit Heater coolant pump failure	Refer to the electrical circuit diagrams and check the fuel fired booster heater water pump and circuit for short to power, open circuit Repair the circuit or check and install a new fuel fired booster heater water pump as required Fuel Fired Booster Heater Coolant PumpRefer to Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D28-11	Fuel Pre-heater - circuit short to ground	NOTE: The pre heat is performed by the ignition glow plug Fuel fired booster heater glow plug internal fault	Carry out circuit checks, inspect the glow plug cables and connector Check and install a new fuel fired booster heater glow plug as required Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D28-15	Fuel Pre-heater - circuit short to battery or open	NOTE: The pre heat is performed by the ignition glow plug Fuel fired booster heater glow plug internal fault	Carry out circuit checks, inspect the glow plug cables and connector Check and install a new fuel fired booster heater glow plug as required Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D29-93	No Start, Even After Restart Attempt - no operation	No fuel present at fuel fired booster heater module Exhaust system blocked Air intake blocked	Check vehicle fuel level Check fuel lines to fuel fired booster heater module for blockage, kinking or damage Check exhaust system and air intake for blockage, kinking or damage Check fuel for aeration and correct fuel delivery Check vehicle is not parked on an incline when parking heater is operated Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D30-93	No Start In Test Mode - no operation	No fuel present at fuel fired booster heater module Exhaust system blocked Air intake blocked	Check vehicle fuel level Check fuel lines to fuel fired booster heater module for blockage, kinking or damage Check exhaust system and air intake for blockage, kinking or damage Check fuel for aeration and correct fuel delivery Check vehicle is not parked on an incline when parking heater is operated Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D31-94	Flame Detected Prior to Normal Operation - unexpected operation	NOTE: The glow plug and flame sensor are a combined unit Glow plug circuit fault	Check exhaust system and air intake for blockage, kinking or damage Carry out circuit checks, inspect the glow plug cables and connector. Repair the circuit or check and install a new fuel fired booster heater glow plug as required Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D32-92	Multiple Flame Interruption During Heating Cycle - performance or incorrect operation	No fuel present at fuel fired booster heater module Exhaust system blocked Air intake blocked	Check vehicle fuel level Check fuel lines to Fuel fired booster heater module for blockage, kinking or damage Check exhaust system and air intake for blockage, kinking or damage Check fuel for aeration and correct fuel delivery Check vehicle is not parked on an incline when parking heater is operated Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D33-92	Flame Interruption During Normal Operation - performance or incorrect operation	No fuel present at fuel fired booster heater module Exhaust system blocked Air intake blocked	Check vehicle fuel level Check fuel lines to fuel fired booster heater module for blockage, kinking or damage Check exhaust system and air intake for blockage, kinking or damage Check fuel for aeration and correct fuel delivery Check vehicle is not parked on an incline when parking heater is operated Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D34-68	Heater In Lock Out Mode - event information	Fuel fired booster heater system fault	NOTE: For information only, rectify other stored fuel fired booster heater diagnostic trouble codes prior to this diagnostic trouble code Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for stored diagnostic trouble codes Check for correct operation
B1D63-11	External Control Relay - circuit short to ground	Fuel fired booster heater module failure	Check and install a new fuel fired booster heater module as required Refer to the warranty policy and procedures information, or determine if any prior approval program is in operation, prior to the installation of a new module/component
B1D63-15	External Control Relay - circuit short to battery or open	Fuel fired booster heater module failure	Check and install a new fuel fired booster heater module as required Refer to the warranty policy and procedures information, or determine if any prior approval program is in operation, prior to the installation of a new module/component
U0010-00	Medium Speed CAN Communication Bus - no sub type information	Medium speed CAN communication bus off	Using the manufacturer approved diagnostic system, complete a CAN network integrity test
U0028-08	Vehicle Communication Bus A - Bus Signal / Message Failures	Medium speed CAN communication bus off Fuel fired booster heater module failure	Using the manufacturer approved diagnostic system, complete a CAN network integrity test
U0300-00	Internal Control Module Software Incompatibility - no sub type information	Fuel fired booster heater module not configured or incorrectly configured	Re-configure the fuel fired booster heater module using the manufacturer approved diagnostic system (Module programming/Configure existing module/Auxiliary heater control module)
U1A37-87	Crash Status Telegram Bus Signal / Message Failures Missing message	Crash signal received over CAN network	NOTE: Event information - the restraints control module has recorded a crash event Using the manufacturer approved diagnostic system, check other modules for related diagnostic trouble codes
U2101-00	Control Module Configuration Incompatible - no sub type information	Fuel fired booster heater module not configured or incorrectly configured Central junction box not configured correctly	Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for reoccurrence of the diagnostic trouble code If the diagnostic trouble code returns Using the manufacturer approved diagnostic system check and up-date the car configuration file as required Re-configure the Fuel fired booster heater module using the manufacturer approved diagnostic system Check for stored diagnostic trouble codes Check for correct operation
U3000-16	Control Module - circuit voltage below threshold	Fuel fired booster heater module power circuit fault Battery/charging system fault	Check other modules for related diagnostic trouble codes If other modules contain low voltage related diagnostic trouble codes, suspect a common cause (battery/charging system fault) If not, refer to the electrical circuit diagrams and check the power and ground circuits to the fuel fired booster heater module Check for stored diagnostic trouble codes Check for correct operation
U3000-17	Control Module - circuit voltage above threshold	Charging system fault Fuel fired booster heater module failure	Check other modules for related diagnostic trouble codes If other modules contain high voltage related diagnostic trouble codes, suspect a common cause (battery/charging system fault) If not, refer to the electrical circuit diagrams and check the power and ground circuits to the fuel fired booster heater module Check for stored diagnostic trouble codes Check for correct operation
U3000-43	Control Module - special memory failure	Fuel fired booster heater module failure	Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for reoccurrence of the diagnostic trouble code If the diagnostic trouble code returns Install a new fuel fired booster heater module as required Refer to the warranty policy and procedures information, or determine if any prior approval program is in operation, prior to the installation of a new module/component
U3000-49	Control Module - internal electronic failure	Fuel fired booster heater module failure	Using the manufacturer approved diagnostic system, record then clear any stored diagnostic trouble codes then conduct the fuel fired booster heater operation test (Setup and configuration/auxiliary heater/operation test) Check for reoccurrence of the diagnostic trouble code If the diagnostic trouble code returns Install a new fuel fired booster heater module as required Refer to the warranty policy and procedures information, or determine if any prior approval program is in operation, prior to the installation of a new module/component
U3003-62	Battery Voltage - signal compare failure	There is a difference of more than 2 volts between the power supply to the fuel fired booster heater and the battery voltage value broadcast via the CAN bus	Check other modules for related diagnostic trouble codes If other modules contain voltage related diagnostic trouble codes, suspect a common cause (battery/charging system fault) If not, refer to the electrical circuit diagrams and check the power and ground circuits to the fuel fired booster heater module