how to diagnose C1234 error code on Ford F-150 13th Generation (2015-2020)

Solution

1. Preparation

• Gather tools and parts needed for repairs.
• Park the vehicle on a level surface, engage the parking brake, and disconnect the battery.

2. Inspect Wiring and Connectors

• Tools Required: Socket set, multimeter, wire brush, dielectric grease.
• Check the ABS wiring harness and connectors for damage.
  • Sub-steps:
    1. Remove any protective covers to access the wiring.
    2. Visually inspect for frayed wires or corrosion.
    3. Clean any corroded connectors with a wire brush and apply dielectric grease to prevent future corrosion.

3. Test Wheel Speed Sensors

• Tools Required: Multimeter.
• Check resistance of each wheel speed sensor.
  • Sub-steps:
    1. Disconnect the electrical connector from each wheel speed sensor.
    2. Set the multimeter to the resistance (ohms) setting.
    3. Measure the resistance across the sensor terminals; it should be within manufacturer specifications (usually 1,000 to 2,000 ohms).
    4. Replace any sensor that is out of specification.

4. Inspect Reluctor Rings

• Tools Required: Inspection mirror, flashlight.
• Check the reluctor rings for any damage.
  • Sub-steps:
    1. Remove the wheel and brake components to access the reluctor ring.
    2. Inspect for cracks, breaks, or debris.
    3. Clean any debris from the reluctor ring with a soft brush.

5. Reconnect and Test

• Tools Required: Torque wrench.
• Reconnect all components and perform a test drive.
  • Sub-steps:
    1. Reconnect the battery and ensure all connections are secure.
    2. Start the vehicle and check for warning lights.
    3. Perform a test drive to confirm the ABS is functioning properly.
    4. Re-check for error codes using the OBD-II scanner.