why does my Toyota Highlander Fourth Generation (2020-present) ABS light keep coming on

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the vehicle to cool down if it has been in use.

2. Scan for Codes

• Use an OBD-II scanner to retrieve any stored codes.
  • Tools Required: OBD-II scanner
  • Sub-steps:
    1. Connect the scanner to the OBD-II port.
    2. Turn on the ignition without starting the engine.
    3. Follow the scanner instructions to read codes.

3. Inspect ABS Fuses

• Check the condition of the ABS fuses.
  • Tools Required: Fuse puller or pliers
  • Sub-steps:
    1. Locate the fuse box and identify the ABS fuse.
    2. Remove the fuse and inspect for continuity.
    3. Replace any blown fuses with the correct amperage rating.

4. Examine Wheel Speed Sensors

• Inspect each ABS wheel speed sensor for damage or dirt.
  • Tools Required: Socket set, cleaning brush
  • Sub-steps:
    1. Lift the vehicle and remove the wheels for better access.
    2. Locate the wheel speed sensors at each wheel hub.
    3. Clean any dirt or debris from the sensors.
    4. Ensure sensors are securely connected and free from damage.

5. Test ABS Hydraulic Control Unit

• Assess the ABS hydraulic control unit functionality.
  • Tools Required: Multimeter, brake fluid
  • Sub-steps:
    1. Check the fluid level in the brake master cylinder.
    2. Using a multimeter, test the wiring to the ABS unit for proper voltage.
    3. If necessary, bleed the brake system to remove air bubbles.

6. Reconnect Battery and Clear Codes

• Reconnect the battery and clear any diagnostic codes.
  • Sub-steps:
    1. Reconnect the negative battery terminal.
    2. Use the OBD-II scanner to clear any DTCs.
    3. Perform a test drive to ensure the ABS light does not reappear.