When your 2022 GMC Acadia displays the P0303 code, the engine control module has identified consistent misfires in cylinder 3. The 2022 Acadia uses GM's proven 3.6L V6 engine, which has well-documented diagnostic procedures.
3.6L V6 Engine Layout
The 2022 Acadia's 3.6L LGX V6 positions cylinder 3 on the driver's side (left) bank, at the rear position. This transverse-mounted engine has good access to ignition components for testing and replacement.
Typical Causes
- Ignition Coil Failure: Coil-on-plug design means isolated failures affect single cylinders
- Spark Plug Wear: GM's iridium plugs eventually require replacement
- Fuel Injector Issues: Direct injection systems can develop spray pattern problems
- Intake Manifold Leaks: Manifold gasket or vacuum line failures
- Carbon Deposits: GDI technology contributes to intake valve fouling
Diagnostic Steps
Connect a diagnostic scanner to access misfire data. Monitor cylinder 3 misfire counts compared to other cylinders. Perform ignition coil swap tests. Check fuel trim data for lean conditions indicating vacuum leaks.
Repair Solutions
Replace failed ignition coils with AC Delco components. Install spark plugs at recommended intervals. Address fuel injector cleaning or replacement as needed. Repair intake system leaks. Consider intake valve cleaning for high-mileage vehicles.