how to diagnose C1201 code in Toyota Highlander Third Generation (2014-2019)

Solution

1. Preparation

• Gather the necessary tools and parts.
• Ensure the vehicle is on a flat surface and securely lifted if required.
• Disconnect the battery to prevent any electrical shorts.

2. Inspect and Clean ABS Sensors

• Tools Required: Socket set, cleaning brush, brake cleaner.
• Remove the wheels to access the ABS wheel speed sensors.
• Clean the sensor area with a brush and brake cleaner to remove debris.
• Reinstall the wheels and lower the vehicle.

3. Check and Replace Brake Fluid

• Tools Required: Brake fluid tester or hydrometer, funnel.
• Check the brake fluid level; if low, fill it to the recommended level using the appropriate brake fluid type (DOT 3 or DOT 4).
• If the fluid is contaminated (dark or cloudy), perform a brake fluid flush.

4. Inspect Brake Pedal Switch

• Tools Required: Multimeter.
• Locate the brake pedal switch and remove it from its mounting.
• Use a multimeter to check continuity when the pedal is pressed and released; replace if faulty.

5. Repair Wiring and Connectors

• Tools Required: Wire stripper/crimper, electrical tape.
• Inspect wiring and connectors for breaks or corrosion.
• Repair any damaged wiring or connectors using solder or appropriate connectors and cover with electrical tape.

6. Test the ABS Module

• Tools Required: OBD-II scanner with ABS functions.
• Use the scanner to initiate a self-diagnosis of the ABS module.
• Follow on-screen prompts to check for any additional faults; rectify as necessary.