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 terminal of the battery to prevent electrical shock.
• Ensure the vehicle is on a flat surface and properly supported with jack stands.

2. Inspect ABS Wheel Speed Sensors

• Tools Required: Socket set, multimeter
• Remove the wheel to access the wheel speed sensor.
• Visually inspect the sensor for damage or debris.
• Use a multimeter to check the sensor's resistance; it should typically be within manufacturer specifications.
• If faulty, replace the sensor with a new one.

3. Check ABS Module and Wiring

• Remove any covers or panels to access the ABS module.
• Check for stored fault codes using the OBD-II scanner; note any specific codes.
• Visually inspect the wiring harness and connectors for signs of wear or corrosion.
• Clean or repair any damaged connections.

4. Brake Fluid Inspection

• Tools Required: Brake fluid tester or hydrometer
• Check the brake fluid reservoir level; top off with the manufacturer-specified brake fluid if low.
• Test the brake fluid for moisture content; if it exceeds 3%, replace the brake fluid.

5. Reassemble and Test

• Reinstall any removed components and the wheel.
• Reconnect the negative battery terminal.
• Start the vehicle and check if the ABS light remains illuminated.