B2455 — Aux Heater Blower Faulted #

Note: The wording of this DTC may vary depending on the vehicle manufacturer.

• B2455 — Auxiliary Heater Blower Faulted (Ford, Jaguar, Land Rover)
• B2455 — Auxiliary HVAC Blower Control Circuit Malfunction (GM/Chevrolet)
• B2455 — Auxiliary Blower Motor Circuit Fault (Chrysler)

Summary for code B2455 #

The B2455 “Aux Heater Blower Faulted” diagnostic trouble code (DTC) is triggered when the vehicle’s onboard diagnostic system detects a malfunction in the auxiliary heater blower circuit. The auxiliary heater blower is an electric fan, usually located in the rear or under-seat area, designed to circulate warm air independently of the main HVAC (Heating, Ventilation, and Air Conditioning) system. When the control module senses an unexpected electrical value—such as an open circuit, short, or improper voltage—it logs B2455 and may limit auxiliary heating operation. The code points specifically to wiring, control, or component issues in the auxiliary heater blower circuit. This is a comfort-related fault, but it can signal deeper electrical or HVAC problems if ignored.

Frequent symptoms for code B2455 #

If your vehicle registers a B2455 code, you’ll likely notice some telltale signs related to cabin comfort and airflow. These symptoms can sometimes be subtle, especially in mild weather, but become more apparent in cold conditions or when rear passenger heating is needed. Common symptoms include:

• No airflow or reduced airflow from rear/auxiliary vents
• Auxiliary heater not producing warm air
• Blower fan not responding to speed changes
• HVAC warning light or check engine light (in some models)
• Unusual noises from auxiliary blower area (in rare cases)

Probable causes for code B2455 #

The B2455 code is most frequently caused by electrical or component issues within the auxiliary heater blower circuit. Understanding the likely culprits helps streamline your diagnosis and repair process. Here’s what usually goes wrong, in order of likelihood:

1. Faulty auxiliary blower motor (motor windings worn or seized)
2. Blower motor resistor or control module failure (burned out or open circuit)
3. Damaged wiring or poor electrical connections (corrosion, pinched wires, loose connectors)
4. Blown fuse or failed relay in auxiliary blower circuit
5. HVAC control module fault (rare, but possible if other issues are ruled out)

Step-by-step diagnostic for code B2455 #

Diagnosing a B2455 code is a process of elimination, starting with the most accessible and likely causes. Here’s a stepwise approach, suitable for both DIYers and professional technicians:

• Check for additional codes: Scan for other HVAC or body control module (BCM) codes that might provide supporting clues.
• Inspect fuses and relays: Locate the auxiliary blower fuse and relay; replace if blown or defective.
• Visual inspection: Examine wiring and connectors between the auxiliary blower motor and the control module for corrosion, damage, or loose pins.
• Test the blower motor: Apply direct battery voltage to the auxiliary blower motor to verify operation. If it does not spin, replace it.
• Check the blower resistor/module: Use a multimeter to measure resistance and continuity. Replace if readings are out of spec or open.
• Check for voltage at the blower connector: With the HVAC system on, verify that the appropriate voltage reaches the blower motor connector. No voltage may indicate a wiring or module issue.
• Evaluate the HVAC control module: If all else checks out, the problem may be an internal fault in the control module. Advanced scan tools may be needed for further diagnosis.

Possible repairs for code B2455 #

Remedies for a B2455 code focus on restoring proper function to the auxiliary heater blower circuit. The appropriate fix depends on your diagnostic findings. Common repairs include:

• Replacing a faulty auxiliary blower motor
• Replacing a burned-out blower resistor or control module
• Repairing or replacing damaged wiring/connectors
• Replacing a blown fuse or faulty relay
• Repairing or reprogramming the HVAC control module (rare)

Is it safe to drive with code B2455? #

Yes, but with limitations. The B2455 code does not affect core vehicle safety or drivability. However, you may experience reduced comfort—especially in cold weather—because the auxiliary heater blower may not function. If you rely on rear or auxiliary heating for passengers, or if you notice unusual electrical symptoms, address the issue promptly to prevent further inconvenience or potential electrical faults.

Vehicles most frequently affected by code B2455 #

While the B2455 code can appear in various makes and models, it is most commonly reported in vehicles equipped with separate rear or auxiliary HVAC systems. OEMs that use this code or similar wording include:

• Ford (Expedition, Transit, Explorer with rear HVAC)
• Land Rover and Jaguar SUVs (Range Rover, Discovery, F-Pace)
• GM/Chevrolet (Suburban, Tahoe, Yukon with rear climate control)
• Chrysler/Dodge minivans (Grand Caravan, Pacifica)
• Some Mercedes-Benz vans and SUVs with auxiliary heating

Common mistakes & best practices for code B2455 #

Misdiagnosis of B2455 often results from overlooking simple issues or skipping key steps. Keep these tips in mind to avoid wasted time and expense:

• Don’t replace the blower motor before checking fuses and relays—these are quicker, cheaper fixes.
• Always inspect wiring and connectors for visible damage or corrosion, especially in areas prone to moisture.
• Test the blower motor directly; don’t assume it’s bad based only on the DTC.
• Use a wiring diagram to trace the circuit fully if initial checks don’t reveal the cause.
• Clear the code after repairs and retest the system to confirm the fix.

Express FAQ for code B2455 #

Here are quick answers to the most common questions about B2455:

• Q: Will clearing the code restore my auxiliary heater blower?
• A: No. Clearing the code without addressing the root cause will only temporarily remove the warning. The code—and symptoms—will return until the fault is fixed.
• Q: Can a bad auxiliary blower drain my battery?
• A: Rarely. A seized or shorted blower motor could draw excessive current, but in most cases, the system disables the blower to protect the circuit. Always check for electrical issues if you notice unusual battery drain.