how to fix B1791 code in Toyota RAV4 XA40 (2013-2018)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the ignition is off.
• Disconnect the vehicle battery to ensure safety.

2. Inspect and Replace Key Fob Battery

• Sub-steps:
  1. Remove the key fob cover using a small flathead screwdriver.
  2. Replace the old battery (usually a CR2032) with a new one, ensuring correct polarity.
  3. Reassemble the key fob.

3. Check Smart Key Antenna

• Sub-steps:
  1. Locate the smart key antenna module (usually located under the dashboard near the steering column).
  2. Inspect the antenna for any physical damage or disconnections.
  3. Reconnect any loose wiring or replace the antenna if damaged.

4. Reprogram Key Fob

• Sub-steps:
  1. Insert the key into the ignition and turn it to the "ON" position without starting the engine.
  2. Press and hold the "LOCK" button on the key fob for 1 second, then release.
  3. Turn the ignition to "OFF" and remove the key.
  4. Test the key fob functionality.

5. Clear Codes

• Sub-steps:
  1. Reconnect the vehicle battery.
  2. Use the OBD-II scanner to clear any stored trouble codes.
  3. Test drive the vehicle to confirm that the issue is resolved.

Tools Required:

• OBD-II scanner
• Small flathead screwdriver
• Multimeter (for battery testing)

Parts Required:

• Key fob battery (CR2032)
• Smart key antenna (if needed)

Estimated Repair Time: 1-2 hours

Safety Warnings:

• Disconnect battery before working on electrical systems to prevent accidental shorts.
• Allow the vehicle to sit for a few minutes after disconnecting the battery to ensure all systems power down.