how to troubleshoot B2784 code on Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather tools and parts: OBD-II scanner, multimeter, replacement key fob battery, and basic hand tools.
• Ensure the vehicle is in a safe working environment and the ignition is turned off.

2. Inspect Key Fob

• Sub-step 1: Open the key fob using a flathead screwdriver to access the battery compartment.
• Sub-step 2: Remove the old battery and replace it with a new one of the same type (usually CR2032).
• Sub-step 3: Reassemble the key fob, ensuring all clips are secured.

3. Check Vehicle Battery

• Sub-step 1: Use a multimeter to measure the voltage at the vehicle battery terminals.
• Sub-step 2: If voltage is below 12.4 volts, charge the battery or replace it if necessary.
• Sub-step 3: Recheck the connections for corrosion or loose terminals and clean as needed.

4. Inspect Keyless Entry Antenna

• Sub-step 1: Locate the keyless entry antenna, typically located near the ignition switch or under the dashboard.
• Sub-step 2: Inspect the wiring harness and connectors for signs of damage or corrosion.
• Sub-step 3: Repair any damaged wires and ensure the connections are secure.

5. Reprogram Key Fob

• Sub-step 1: Insert the key into the ignition and turn it to the "ON" position without starting the engine.
• Sub-step 2: Follow the manufacturer’s procedure for reprogramming the key fob (consult owner’s manual for specifics).
• Sub-step 3: Test the key fob to ensure it now operates the vehicle’s locks and ignition.