2024 Jeep Wrangler Check Engine Light P04B5

Symptoms

Owners of 2024 Jeep Wrangler and Grand Cherokee vehicles may observe the Malfunction Indicator Lamp (MIL) or Check Engine Lamp (CEL) illuminated on their dashboard. This warning light indicates a potential issue detected by the vehicle's onboard diagnostic system. The customer's complaint may specifically be a "MIL-On" or "CEL-On" condition.

Fault Codes / DTCs

When the MIL or CEL is illuminated, a diagnostic scan may reveal the following Diagnostic Trouble Code (DTC) stored in the Powertrain Control Module (PCM):

• P04B5-FUEL FILL DOOR STUCK OPEN: This code specifically points to a problem with the fuel fill door system, indicating that the vehicle's computer believes the fuel door is not properly closed or is stuck open.

Diagnosis and Trigger Conditions

Before any repair, technicians are advised to record all present DTCs and Wi-Tech Freeze Frame Data, then run and save a Vehicle Scan Report. This initial step helps to capture a snapshot of the vehicle's condition at the time the fault occurred.

If the DTC P04B5 is stored in the PCM, technicians should check the number of "Good Trips" using a scan tool. The "Good Trip" count can be found under the Environmental Data of each DTC. Three good trips are typically required for the MIL to turn off. A specific drive evaluation must be performed to complete these good trips and ensure the MIL is extinguished by the start of the Fourth Trip, with a key cycle performed between each trip.

Repair Procedure Summary

The repair procedure outlined in manufacturer communication S2414000001 Rev. A depends on whether the DTC P04B5 is stored or active.

If DTC P04B5 is Stored

If the P04B5 code is stored, the technician needs to perform a drive evaluation to accumulate "Good Trips." The required drive cycle involves:

• First Trip: Drive more than 16 miles, then maintain a speed above 25 mph for more than 5 minutes.
• Second Trip: After a key cycle, drive above 25 mph for more than 5 minutes.
• Third Trip: After another key cycle, drive above 25 mph for more than 5 minutes.

The Malfunction Indicator Lamp should turn off at the start of the Fourth Trip if the conditions are met.

If DTC P04B5 is Active

If the DTC P04B5 is active, the technician should thoroughly inspect the fuel door area:

1. Check Fuel Door Plunger Tappet: Verify that the fuel door plunger tappet is present on the door. Figure 2 in the communication illustrates a fuel door with a plunger tappet missing. If missing or damaged, repair or replace as necessary.
2. Fuel Door Functionality: Check that the fuel door properly opens and closes. If issues are found, clear the DTC.
3. Plunger Tappet and Solenoid Inspection: If the fuel door does not open or close correctly, but the plunger tappet is present, inspect the plunger tappet and solenoid for proper alignment or damage. Figure 3 provides visual guidance on checking the solenoid and tappet for looseness or damage. If an issue is found, replace the fuel door plunger tappet and/or the fuel door housing.
4. Electrical Circuit Check: If no mechanical issues are found with the plunger tappet or solenoid, check the (G66) Fuel Door Status Signal Circuit for a short to ground using service diagnostics.

After any repairs, the code must be cleared with a scan tool, and the same ride evaluation (drive cycle) as described for a stored DTC P04B5 must be performed to verify the repair and ensure the code does not reappear.

Important Warnings

Owners and technicians should be aware of the following advisories from Stellantis:

• "This document does not authorize warranty repairs." This means the information provided is for diagnostic and repair guidance, but it does not automatically guarantee warranty coverage for the repair.
• "STAR Online does not provide any conclusions about what is wrong with the vehicle." The document serves as a record of past experiences, and the technician is responsible for determining the appropriate course of action.
• Anytime the fuel door is opened, the vehicle must be driven more than 16 miles to re-enable the diagnostic. After 16 miles have been accumulated, the vehicle must be driven above 25 mph for more than 5 minutes for the diagnostic to complete.

If a solution is not found after following these procedures, contact the STAR Center or your Technical Assistance Center via TechCONNECT or an eCONTACT ticket.

Owner Action

If your 2024 Jeep Wrangler or Grand Cherokee is displaying a check engine light and you suspect a "FUEL FILL DOOR STUCK OPEN" issue related to DTC P04B5, it is recommended to have your vehicle inspected by an authorized service technician. They have the necessary diagnostic tools and access to manufacturer communications like S2414000001 Rev. A to properly diagnose and resolve the issue.

NHTSA ID: S2414000001