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P0300 on JEEP GLADIATOR

Severity
Medium
NHTSA Reports
6
Most Affected
2020

What P0300 Means on Your JEEP GLADIATOR

Real JEEP GLADIATOR Owner Reports (Source: NHTSA Complaints Database)

"To Whom It May Concern, I hope this message finds you well. I am writing to formally report a serious mechanical failure involving my 2020 Jeep Gladiator (VIN: [XXX] ), which recently experienced a complete engine lock-up without any prior warning signs. The vehicle is now inoperable."

— 2020 JEEP GLADIATOR owner • ENGINE • Filed 07/08/2025

"To Whom It May Concern, I am writing to formally report a serious mechanical issue involving my 2020 Jeep Gladiator (VIN: [XXX] rienced a complete and unexpected engine lock-up. The vehicle is now undrivable and presents both a functional and potential safety concern."

— 2020 JEEP GLADIATOR owner • ENGINE • Filed 07/08/2025

"Error Codes P0300, 301,305, 420. Driving on the interstate I got the CEL light. One point during driving when the 420 code came in vehicle went into limp mode and speed was greatly reduced in 70 mph traffic. Luckily I was able to get to the side of the road so no accident happened."

— 2020 JEEP GLADIATOR owner • ENGINE • Filed 09/01/2022

"Starting at just over 100 miles my vehicle started displaying a electronic start/stop systems errors and the check engine light came one. the cel was caused by engine misfires and show code p0300."

— 2020 JEEP GLADIATOR owner • ENGINE • Filed 08/25/2020

"On my 2020 jeep gladiator rubicon ess and check engine light came on at 249 miles. check engine light code was p0300 multiple cylinder misfire. took it to the dealer monroe dodge and they replaced the battery for ess and did a recommended pcm flash for the check engine light."

— 2020 JEEP GLADIATOR owner • ENGINE • Filed 08/27/2020

Data from NHTSA Vehicle Complaints Database. All reports are filed by vehicle owners directly with the U.S. Department of Transportation.

Common Causes of P0300 on JEEP GLADIATOR

100%

Percentages based on NHTSA complaint component analysis for this vehicle.

Complaint Trend by Year

2020
6

What To Do Next

  1. 1
    Check for recalls on YOUR VIN

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if your vehicle is covered.

  2. 2
    Get a proper diagnosis

    A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50-$150) pinpoints the root cause before you spend money on parts.

  3. 3
    Compare repair quotes

    Get 2-3 quotes. Dealer vs independent shop prices often differ 30-50% for the same repair.

P0300 on Other Vehicles

Data sourced from the National Highway Traffic Safety Administration (U.S. Department of Transportation) and the SAE J2012 OBD-II standard. Code definitions follow the SAE J2012 / ISO 15031-6 standard. Owner reports are filed directly with NHTSA by vehicle owners. This information is provided for educational purposes only and should not replace professional automotive diagnosis. Always consult a qualified mechanic for vehicle repair decisions.

Last updated: March 2026