When your 2023 Jeep Gladiator displays the P0305 code, the engine control module has detected repeated misfires in cylinder 5. The 2023 Gladiator continues with the 3.6L Pentastar V6 as its sole gasoline engine (EcoDiesel was discontinued). With six cylinders, P0305 is a legitimate diagnostic code.
2023 Gladiator Powertrain
The 2023 Gladiator uses the 3.6L Pentastar V6 producing 285 horsepower across all trims. The EcoDiesel option was discontinued after 2022. All 2023 Gladiators use this same V6 configuration.
Cylinder 5 Location
On the Pentastar V6, cylinder 5 is on the driver side bank toward the rear. Stellantis V6 engines place odd-numbered cylinders on the driver side.
Common Causes
Spark plug wear can occur with demanding use including towing and off-roading. Ignition coil failure at cylinder 5 is possible. Fuel injector issues may cause lean misfires. Vacuum leaks around the intake affect individual cylinder performance.
Diagnostic Process
Read all codes and freeze frame data. Inspect cylinder 5's spark plug and ignition coil. Test coil function with swap testing. Check for vacuum leaks. Verify fuel injector operation.