B1946 – OBD-II DTC

OBD-II DTC B1946 – Climate Control A/C Post Evaporator Sensor Circuit Failure

DTC B1946 meaning

DTC B1946 refers to a fault in the Climate Control A/C Post Evaporator Sensor Circuit. This diagnostic trouble code indicates that the vehicle’s onboard diagnostic system has detected an issue with the sensor responsible for monitoring the temperature of the air after it passes through the evaporator. The post evaporator sensor plays a crucial role in regulating the air conditioning system’s performance and ensuring optimal cabin comfort.

DTC B1946 symptoms

Common symptoms associated with DTC B1946 may include:

• Inconsistent or inadequate cooling from the A/C system
• Unusual fluctuations in cabin temperature
• Increased humidity levels inside the vehicle
• Possible A/C system failure or malfunction
• Illumination of the check engine light or A/C warning light

DTC B1946 causes

Several factors can lead to the occurrence of DTC B1946, including:

• Faulty post evaporator temperature sensor
• Wiring issues, such as shorts or open circuits in the sensor circuit
• Corrosion or poor connections at the sensor or related connectors
• Malfunctioning A/C control module
• Software issues within the vehicle’s control systems

DTC B1946 seriousness

The seriousness of DTC B1946 can vary depending on the symptoms experienced. While it may not pose an immediate safety risk, it can lead to:

• Reduced comfort due to ineffective climate control
• Potential damage to the A/C system if left unaddressed
• Increased energy consumption and strain on the vehicle’s electrical system

It is advisable to diagnose and repair the issue promptly to maintain optimal vehicle performance.

How to diagnose DTC B1946

To diagnose DTC B1946, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC B1946.
2. Inspect the post evaporator sensor and its wiring for visible damage or corrosion.
3. Check the sensor’s resistance and compare it to manufacturer specifications.
4. Test the voltage supply to the sensor with a multimeter.
5. Examine the A/C control module for any faults or software issues.
6. Clear the DTC and perform a road test to see if the code reappears.

How to fix DTC B1946 step-by-step instructions

To fix DTC B1946, follow these step-by-step instructions:

1. Confirm the DTC using an OBD-II scanner.
2. Inspect the post evaporator sensor and wiring for any visible damage.
3. If the sensor is faulty, replace it with a new one.
4. Repair any damaged wiring or connectors in the sensor circuit.
5. Ensure all connections are clean and secure.
6. Recheck the sensor’s resistance and voltage supply after repairs.
7. Clear the DTC using the OBD-II scanner.
8. Perform a road test to verify that the issue has been resolved.

How to erase DTC B1946

To erase DTC B1946, 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 menu on the scanner.
4. Select the option to clear or erase trouble codes.
5. Confirm the action and wait for the scanner to complete the process.
6. Disconnect the scanner and start the vehicle to ensure the code does not reappear.

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.