how to diagnose B1242 code on Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the vehicle to cool down before working on the electrical system.

2. Inspect and Clean Connections

• Sub-steps:
  • Remove the battery terminals (negative first, then positive).
  • Clean any corrosion from the terminals and battery posts using a wire brush.
  • Reconnect the battery terminals securely (positive first, then negative).

3. Replace the Battery Voltage Sensor

• Sub-steps:
  • Locate the battery voltage sensor (usually mounted on the battery or near it).
  • Disconnect the sensor connector.
  • Remove any mounting screws and take out the old sensor.
  • Install the new battery voltage sensor in reverse order, ensuring it is securely fastened.
  • Reconnect the sensor connector.

4. Reconnect Battery and Test

• Sub-steps:
  • Reconnect the negative battery terminal.
  • Start the engine and monitor the dashboard for warning lights.
  • Use the OBD-II scanner to clear the B1242 code and check for any reoccurrence.

Tools Required:

• OBD-II scanner
• Multimeter
• Wire brush
• Socket set
• Torque wrench (if required for sensor installation)

Parts Required:

• New battery voltage sensor

Estimated Repair Time: 1-2 hours

Safety Warnings:

• Disconnect the battery before handling any electrical components to prevent shocks or shorts.