how to resolve the B1242 code in my Toyota RAV4 XA50 (2019-2024)

Solution

1. Preparation

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

2. Recharge A/C System

• Tools Required: A/C manifold gauge set, refrigerant.
• Attach the manifold gauge set to the A/C service ports.
• Check the low and high-side pressures to confirm if they are within specifications.
• If low, add the appropriate refrigerant as per the vehicle's specifications (R-134a or R-1234yf).
• Monitor the pressures during the recharge process.

3. Replace A/C Refrigerant Pressure Sensor

• Tools Required: Socket set, torque wrench, vacuum pump (if needed).
• Locate the A/C refrigerant pressure sensor, typically found on the A/C line.
• Disconnect the electrical connector from the sensor.
• Unscrew the old sensor using a socket wrench.
• Install the new sensor and tighten to the manufacturer’s specifications (usually around 15-20 ft-lbs).
• Reconnect the electrical connector securely.

4. Clear Error Codes

• Reconnect the vehicle battery.
• Use an OBD-II scanner to clear the B1242 code from the vehicle's computer.
• Start the engine and let it idle while monitoring the A/C system.