my GMC Sierra T1XX (2019-Present) shows C0242 code what should I check

Learn how to diagnose and fix C0242 ABS issue in GMC Sierra T1XX. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and engage the parking brake.
• Disconnect the negative terminal of the battery to ensure safety.

2. Inspect ABS Wheel Speed Sensors

• Remove the wheel on the affected side to access the ABS sensor.
• Clean the sensor and the sensor ring with a brake cleaner to remove any debris.
• Check the sensor gap and ensure it is within the manufacturer's specifications (typically around 0.020 inches).
• Reinstall the wheel and repeat for the other side if necessary.

3. Check Wiring and Connectors

• Visually inspect the wiring harness leading to the ABS module for any frays or damage.
• Unplug the connectors and inspect for corrosion or dirt.
• Use a multimeter to test continuity in the wiring leading to the ABS sensor.

4. Inspect ABS Control Module

• Locate the ABS control module, typically mounted near the brake master cylinder.
• Inspect for any signs of moisture or corrosion on the module connectors.
• If necessary, use a scan tool to perform a module reset.

5. Brake Fluid Inspection

• Check the brake fluid reservoir for proper fluid level and condition.
• If the fluid is dark or contaminated, perform a brake fluid flush and replace with new fluid (DOT 3 or DOT 4 as specified in the owner’s manual).

6. Reconnect Battery and Test

• Reconnect the negative terminal of the battery.
• Start the vehicle and monitor the ABS and traction control lights for any reactivation of the codes.