why is the check engine light on in my Cadillac Escalade T1XX (2021-Present)

Symptoms

• Check engine light illuminated
• Decreased fuel efficiency
• Rough idle or engine misfires
• Unusual noises from the engine compartment
• Loss of power during acceleration
• Increased emissions or exhaust odor

Diagnostic Steps

1. Scan for error codes using an OBD-II scanner to identify specific trouble codes.
2. Check the vehicle’s fluid levels, including engine oil, coolant, and transmission fluid.
3. Inspect the gas cap for proper sealing and wear, as a loose or damaged cap can trigger the light.
4. Examine the air intake system for any leaks or blockages.
5. Inspect the spark plugs and ignition coils for wear or damage.
6. Check the exhaust system for leaks or signs of failure.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Ensure the vehicle is parked on a level surface and secure it with jack stands if needed.

2. Replace Failed Components (based on diagnostic findings)

A. Gas Cap

• Sub-steps:
  • Remove the old gas cap from the fuel filler neck.
  • Install the new gas cap ensuring it clicks into place securely.

B. Spark Plugs

• Tools Required: Socket set, torque wrench
• Sub-steps:
  • Remove the ignition coil(s) by unscrewing the mounting bolts.
  • Unscrew the old spark plugs using a socket.
  • Install new spark plugs by hand, then torque to manufacturer specifications (usually around 13-15 lb-ft).
  • Reattach the ignition coil(s).

C. Air Filter

• Sub-steps:
  • Open the air intake cover and remove the old air filter.
  • Clean the housing if necessary.
  • Install the new air filter, ensuring it fits snugly.

D. Exhaust Leak Repair

• Sub-steps:
  • Inspect the exhaust system visually and with your hand for leaks.
  • If leaks are found, replace any damaged gaskets or pipe sections as necessary.
  • Use a torque wrench to ensure all bolts are tightened to manufacturer specifications.

3. Reconnect Battery

• Reconnect the battery terminals, ensuring they are tight and free of corrosion.