B1249 – Blend Door Failure

The ODBII code B1249 indicates a blend door failure, which means there is a malfunction in the system that controls the mixing of hot and cold air in the vehicle’s heating and air conditioning system.

The severity of ODBII code B1249 Blend Door Failure is moderate.

Common Causes For: B1248 Passenger’s Seatback Autoglide Rearward Switch Circuit Short to Ground

• Faulty blend door actuator
• Broken blend door
• Electrical connection issues
• Vacuum leaks
• Malfunctioning climate control module
• Obstructions in the blend door mechanism
• Wiring harness damage

Common misdiagnosis for B1249 Blend Door Failure

• Faulty HVAC control module
• Electrical wiring issues
• Blown fuses
• Faulty temperature sensors
• Malfunctioning actuator motors
• Refrigerant issues
• General HVAC system failure

Common Troubleshooting Steps

The OBD-II code B1249 typically indicates a blend door failure, which is related to the vehicle’s heating, ventilation, and air conditioning (HVAC) system. The blend door is responsible for directing airflow through the heater core or the air conditioning evaporator, allowing for temperature control inside the vehicle. Here are some common troubleshooting steps to address this issue:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue.
• Inspect the HVAC Control Module: Ensure that the HVAC control module is functioning properly. Look for any signs of damage or corrosion in the connectors and wiring.
• Examine the Blend Door Actuator: The blend door actuator is responsible for moving the blend door. Check if the actuator is receiving power and is functioning correctly. You can do this by:
• Listening for any clicking or grinding noises when the HVAC system is activated.
• Manually testing the actuator to see if it moves the blend door.
• Check for Obstructions: Inspect the blend door and its housing for any obstructions or debris that may be preventing it from moving freely.
• Inspect the Blend Door: If accessible, check the blend door itself for any physical damage or misalignment. A broken or stuck blend door can cause the system to fail.
• Test the Wiring and Connectors: Inspect the wiring and connectors leading to the blend door actuator and HVAC control module for any signs of damage, corrosion, or loose connections.
• Check the Climate Control Settings: Ensure that the climate control settings are correctly configured. Sometimes, incorrect settings can lead to blend door issues.
• Reset the HVAC System: In some cases, resetting the HVAC system by disconnecting the battery for a few minutes may help clear any temporary faults.
• Consult the Service Manual: Refer to the vehicle’s service manual for specific troubleshooting procedures and specifications related to the HVAC system and blend door operation.
• Professional Diagnosis: If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who can perform more advanced diagnostics and repairs. By following these steps, you should be able to identify and potentially resolve the issue related to the B1249 blend door failure code.