When your 2022 Jeep Grand Cherokee displays P0306 diagnostic trouble code, the engine control module has detected misfires occurring in cylinder 6. The 2022 Grand Cherokee WL introduced an all-new platform with multiple engine options, all featuring six or more cylinders, making P0306 a valid code requiring diagnosis.
2022 Grand Cherokee Engine Configuration
The 2022 Jeep Grand Cherokee offers the 3.6-liter Pentastar V6 producing 290 horsepower and the 5.7-liter HEMI V8 delivering 357 horsepower. Both engines have cylinder 6, though its location differs. The V6 places cylinder 6 on the rear passenger bank, while the V8 positions it mid-rear on the passenger side.
V6 vs V8 Diagnostic Differences
The Pentastar V6 uses a simpler configuration without cylinder deactivation, making misfire diagnosis more straightforward. Standard ignition coil, spark plug, and injector testing applies. The HEMI V8 incorporates Multi-Displacement System (MDS) that deactivates cylinders during cruising, adding complexity to misfire diagnosis when MDS solenoids or lifters may be involved.
Common Misfire Causes
Both engines commonly experience ignition coil failures and spark plug wear. The HEMI may also exhibit MDS-related issues affecting cylinder 6 operation. Fuel injector problems and vacuum leaks can cause lean misfires on either engine.