why does my GMC Sierra T1XX (2019-Present) check engine light keep coming on

• •Check engine light illuminated
• •Rough idle or engine misfire
• •Reduced engine power or performance
• •Poor fuel economy
• •Unusual engine noises (e.g., knocking or pinging)
• •Smell of fuel or exhaust fumes

1. 1Scan for error codes using an OBD-II scanner to identify specific trouble codes.
2. 2Inspect the gas cap for proper sealing; a loose or damaged cap can trigger the check engine light.
3. 3Check engine oil and coolant levels; low levels can indicate leaks or other problems.
4. 4Inspect the air filter for dirt or blockages that could affect performance.
5. 5Review the vehicle’s maintenance records to determine if any scheduled services are overdue.
6. 6Conduct a visual inspection of all major engine components for signs of wear, damage, or loose connections.

After completing the repair, verify that the issue has been resolved:

• ✓Test the affected component to ensure it functions correctly
• ✓Check for any error codes or warning lights
• ✓Monitor the vehicle for a few days to ensure the issue does not recur

To prevent this issue from occurring again:

• •Follow the manufacturer's recommended maintenance schedule
• •Address warning signs early before they develop into major issues
• •Use quality parts and fluids recommended for your vehicle
• •Keep detailed records of all repairs and maintenance

• •OBD-II scanner
• •Socket set
• •Torque wrench
• •Screwdrivers
• •Multimeter

• •Gas cap (if damaged)
• •Air filter (if dirty)
• •Spark plugs (if worn)
• •Oxygen sensors (if faulty)