what does it mean if my Toyota Corolla E140 (2006-2013) throws a C1231 code

Learn how to diagnose and fix C1231 ABS malfunction in Toyota Corolla E140 (2006-2013). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a flat surface and engage the parking brake.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Inspect and Clean Wheel Speed Sensors

• Locate the wheel speed sensors on each wheel assembly.
• Remove any dirt or debris from the sensor area using a soft cloth and appropriate cleaning solution.
• Check the mounting of the sensors to ensure they are securely attached.

3. Test and Replace Wheel Speed Sensors (if necessary)

• Using a multimeter, measure the resistance of each wheel speed sensor:
  • Expected resistance is typically between 1,000 to 2,000 ohms (refer to specific service manual for exact values).
• If a sensor is out of spec, replace it:
  • Remove the sensor from its housing.
  • Install the new sensor by reversing the removal process and ensuring it is properly aligned.

4. Check and Repair Wiring and Connectors

• Inspect the wiring harness leading to the wheel speed sensors for frays or breaks.
• Repair any damaged wiring using appropriate electrical tape or connectors.
• Ensure all connectors are clean and free of corrosion. Use contact cleaner if necessary.

5. Reconnect Battery and Test

• Reconnect the negative battery terminal.
• Start the vehicle and check the ABS warning light.
• Conduct a road test to verify that the ABS and traction control systems are operating correctly.