B2428 – OBD-II DTC

OBD-II DTC B2428 – A/C Post Heater Sensor #2 Circuit Failure

DTC B2428 meaning

DTC B2428 refers to a fault in the A/C Post Heater Sensor #2 Circuit. This diagnostic trouble code indicates that the vehicle’s onboard diagnostic system has detected an issue with the electrical circuit associated with the second post heater sensor in the air conditioning system. The post heater sensor is responsible for monitoring the temperature of the air after it has passed through the heater core, ensuring optimal performance of the HVAC system.

DTC B2428 symptoms

Common symptoms associated with DTC B2428 may include:

• Inconsistent or inadequate heating from the A/C system
• Air conditioning system not functioning properly
• Increased cabin temperature
• Potential activation of the check engine light
• Erratic behavior of the HVAC controls

DTC B2428 causes

Several factors can lead to the triggering of DTC B2428, including:

• Faulty A/C Post Heater Sensor #2
• Wiring issues such as shorts, opens, or corrosion in the circuit
• Connector problems, including loose or damaged connections
• Faulty HVAC control module
• Software issues within the vehicle’s control systems

DTC B2428 seriousness

The seriousness of DTC B2428 can vary depending on the symptoms experienced. While it may not pose an immediate safety risk, it can lead to discomfort due to inadequate heating or cooling in the vehicle. Additionally, ignoring this code may result in further damage to the HVAC system or related components, leading to more costly repairs in the future.

How to diagnose DTC B2428

To diagnose DTC B2428, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC B2428.
2. Inspect the A/C Post Heater Sensor #2 and its wiring for visible damage or corrosion.
3. Check the connectors for secure connections and signs of wear.
4. Test the A/C Post Heater Sensor #2 using a multimeter to ensure it operates within specifications.
5. Examine the HVAC control module for any software updates or faults.
6. Clear the DTC and perform a road test to see if the code returns.

How to fix DTC B2428 step-by-step instructions

To fix DTC B2428, follow these steps:

1. Confirm the diagnosis by checking the A/C Post Heater Sensor #2 and its circuit.
2. If the sensor is faulty, replace it with a new one.
3. Repair any damaged wiring or connectors found during inspection.
4. Ensure all connections are secure and free of corrosion.
5. Reprogram or update the HVAC control module if necessary.
6. Clear the DTC using an OBD-II scanner.
7. Test the A/C system to ensure proper operation and monitor for the return of the code.

How to erase DTC B2428

To erase DTC B2428, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Access the diagnostic trouble codes menu on the scanner.
4. Select the option to clear or erase codes.
5. Confirm the action and wait for the scanner to indicate that the codes have been cleared.
6. Disconnect the scanner and perform a test drive to ensure the code does not return.

Recommended tools for OBD-II diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.