what does code B1421 mean for my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

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

2. Inspect and Test the A/C Refrigerant Temperature Sensor

• Locate the A/C refrigerant temperature sensor, typically situated near the A/C evaporator or accumulator.
• Tools Required: Socket set, multimeter
• Sub-steps:
  1. Unplug the electrical connector from the sensor.
  2. Use a multimeter to measure the resistance of the sensor. Compare the readings to the specifications in the service manual (typically between 2-3.5 kΩ at room temperature).
  3. If the readings are out of specification, proceed to replace the sensor.

3. Replace the A/C Refrigerant Temperature Sensor

• Tools Required: Socket set, torque wrench
• Sub-steps:
  1. Remove the sensor from its mounting location.
  2. Apply thread sealant to the new sensor (if required).
  3. Install the new sensor and tighten it to the manufacturer’s specified torque value (refer to service manual).
  4. Reconnect the electrical connector securely.

4. Refill and Test the A/C System

• Tools Required: A/C refrigerant gauge set, vacuum pump
• Sub-steps:
  1. Check the refrigerant level; add refrigerant as necessary to reach the manufacturer’s specifications.
  2. Use a vacuum pump to evacuate the A/C system for about 30 minutes to remove moisture.
  3. Recharge the A/C system with the correct type and amount of refrigerant.

5. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear any stored codes and test drive the vehicle.