Jeep P04EC
Fuel Tank Side (Powertrain Control Module (PCM), 2.0L), P04EE Evaporative System Very Small Leak Detected - Fuel Tank Side as stored or active. Discussion: Verify the vehicle has n
Quick answer
For the 2021–2022 Jeep Wrangler in the US, verified manufacturer communication S2208000150 associates P04EC with a fuel-tank-side evaporative-system large-leak condition on the 2.0L PCM. The communication describes a MIL and/or “Check Fuel Cap” message and directs inspection of the fuel filler cap and PHEV vapor-system components after confirming no applicable TSBs or field actions.
This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.
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1. What does P04EC mean?
For the 2021–2022 Jeep Wrangler in the US, verified manufacturer communication S2208000150 associates P04EC with a fuel-tank-side evaporative-system large-leak condition on the 2.0L PCM. The communication describes a MIL and/or “Check Fuel Cap” message and directs inspection of the fuel filler cap and PHEV vapor-system components after confirming no applicable TSBs or field actions.
2. Technical explanation
The supplied verified evidence identifies P04EC as: “Evaporative System Large Leak Detected - Fuel Tank Side (Powertrain Control Module (PCM), 2.0L).” The official communication groups P04EC with P04EE, which it identifies as an evaporative-system very-small-leak condition on the fuel-tank side. The evidence does not establish a single failed part or a universal repair.
3. What system is affected?
Fuel-tank-side evaporative-emissions system; the evidence specifically references the PCM, 2.0L, fuel filler cap, and PHEV vapor-system components.
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
- Malfunction Indicator Lamp (MIL) on.
- “Check Fuel Cap” message.
- The communication describes an owner complaint that the MIL remained on after recent vehicle service.
6. Possible causes
- The official communication directs inspection of the fuel filler cap and PHEV vapor-system components.
- A specific underlying cause is not yet established by verified evidence.
7. Can I still drive the vehicle?
Not yet established by verified evidence.
8. Can I charge the vehicle?
Not yet established by verified evidence.
9. What you can safely do
- Check whether the fuel filler cap is properly installed and visibly damaged only if this can be done normally and safely.
- Arrange diagnosis by an authorized Jeep service facility if the MIL or “Check Fuel Cap” message remains present.
- Do not attempt high-voltage or PHEV vapor-system repair procedures yourself.
10. Step-by-step troubleshooting
- Verify whether applicable Technical Service Bulletins or other related field service actions apply.
- Inspect the fuel filler cap.
- Inspect the PHEV vapor-system components, as directed by the official manufacturer communication.
- Further diagnostic steps are not established by the supplied verified evidence.
11. When to contact service
Contact an authorized Jeep service facility for diagnosis, especially if P04EC is stored or active, the MIL is illuminated, or a “Check Fuel Cap” message is displayed.
12. What the service center may check
- Check for applicable TSBs and other related field service actions.
- Inspect the fuel filler cap.
- Inspect PHEV vapor-system components.
13. Possible repair or resolution
- Not yet established by verified evidence. The supplied communication provides inspection direction but does not establish a specific repair outcome.
14. Affected vehicles
- Jeep Wrangler · 2021–2022 · US
15. Related TSBs / service bulletins
- NHTSA Manufacturer Communication S2208000150, released August 2022: addresses MIL on and “Check Fuel Cap” message with P04EC and/or P04EE stored or active; directs verification of applicable TSBs or field actions and inspection of the fuel filler cap and PHEV vapor-system components.
- NHTSA document references supplied: MC-10225351-9999, MC-10229494-9999, and MC-10225214-9999.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified official source: NHTSA Manufacturer Communication S2208000150, published August 19, 2022. https://static.nhtsa.gov/odi/tsbs/2022/MC-10225351-9999.pdf
19. Frequently asked questions
What does P04EC mean on the applicable Jeep Wrangler?
The verified communication defines P04EC as “Evaporative System Large Leak Detected - Fuel Tank Side (Powertrain Control Module (PCM), 2.0L).”
Which vehicles are established by the supplied evidence?
Jeep Wrangler model years 2021–2022 in the US.
Can P04EC cause a Check Fuel Cap message?
The official communication lists MIL on and a “Check Fuel Cap” message as the symptom/vehicle issue while P04EC and/or P04EE may be stored or active.
Is it safe to drive or charge?
Not yet established by verified evidence.