what does B1421 code mean for my Toyota Corolla E140 (2006-2013)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety while working on electrical components.

2. Remove the Air Conditioning Refrigerant Temperature Sensor

• Locate the refrigerant temperature sensor on the AC line.
• Disconnect the electrical connector from the sensor.
• Using the appropriate socket, carefully unscrew the sensor from its housing.
• Tools Required: Socket set, ratchet.

3. Inspect and Replace the Sensor

• Examine the old sensor for any signs of damage or wear.
• If the sensor is faulty, install the new refrigerant temperature sensor by threading it into place and tightening it to the manufacturer's torque specifications (typically 15-20 ft-lbs).
• Reconnect the electrical connector to the new sensor.

4. Recharge the Air Conditioning System (if necessary)

• If refrigerant is low or if you have detected a leak, recharge the AC system with the appropriate type of refrigerant (usually R-134a for this model).
• Follow the manufacturer's guidelines for the correct amount of refrigerant.

5. Reconnect the Battery and Test

• Reconnect the negative battery terminal.
• Start the vehicle and run the AC system to check if the cooling performance has improved and ensure the B1421 code does not reappear.
• Safety Warnings: Ensure the vehicle is off while connecting/disconnecting the battery. Avoid direct contact with refrigerant.