ABS Warning Light Diagnosis for 2021 Chevrolet Silverado 1500 T1XX

Tools Required

• OBD-II scanner
• Multimeter
• Basic hand tools (sockets, wrenches)
• Brake fluid
• Jack and jack stands or vehicle lift
• Safety glasses and gloves

Repair Instructions

Step 1: Clear DTCs

• After diagnosing, clear the DTCs using the OBD-II scanner and take the vehicle for a test drive to see if the ABS warning light reappears.

Step 2: Replace Faulty Wheel Speed Sensor

• If a wheel speed sensor is found to be faulty:
  1. Disconnect the negative battery terminal.
  2. Remove the wheel and tire.
  3. Locate the faulty wheel speed sensor.
  4. Disconnect the sensor’s electrical connector.
  5. Remove the sensor using the appropriate socket.
  6. Install the new sensor and reconnect the wiring harness.
  7. Reinstall the wheel and tire.
  8. Reconnect the negative battery terminal.

Step 3: Repair Wiring Issues

• If damaged wiring is found:
  1. Cut out damaged sections and strip the insulation.
  2. Solder in new wire or use appropriate connectors.
  3. Insulate with heat shrink tubing or electrical tape.

Step 4: Replace ABS Module

• If the ABS module is found to be defective:
  1. Disconnect the battery.
  2. Remove the module’s electrical connector.
  3. Unmount the ABS module from its bracket.
  4. Install the new ABS module and reconnect the wiring.
  5. Reconnect the battery and clear any DTCs.

Step 5: Brake System Bleeding

• After any repairs, especially if brake components were replaced:
  1. Use a brake bleeder kit to remove air from the brake lines.
  2. Start with the wheel furthest from the master cylinder (usually rear passenger).
  3. Ensure the brake fluid reservoir is filled during the process.

Step 6: Final Verification

• After completing repairs, test drive the vehicle to ensure the ABS warning light does not illuminate again and that braking performance is restored.

Conclusion

If the ABS warning light continues to illuminate after performing these checks and repairs, further diagnosis may be required, potentially involving advanced scanning tools or professional assistance.