JEEP
18-062-26
Manufacturer communications
- Publication date
- 2026-06-25
- Received by NHTSA
- 2026-07-02
- NHTSA record numbers
- 11034358
Manufacturer summary
Original wording in English
Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs):
• **P0420 - Catalyst System Efficiency Below Threshold Bank 1.
• P0430 - Catalyst System Efficiency Below Threshold Bank 2.**
• P0456 - EVAP System Small Leak. Customers may also comment on one or more of the following:
• **Vehicle fails emissions inspection testing.**
• Pinging/detonation sound from the engine after warm up at 1000-1500 RPM at low speed. (EMEA and APAC Only).
• The vehicle stalls at low speeds and/or coming to a stop This bulletin involves reprogramming the PCM with the latest available software.
• **P0420 - Catalyst System Efficiency Below Threshold Bank 1.
• P0430 - Catalyst System Efficiency Below Threshold Bank 2.**
• P0456 - EVAP System Small Leak. Customers may also comment on one or more of the following:
• **Vehicle fails emissions inspection testing.**
• Pinging/detonation sound from the engine after warm up at 1000-1500 RPM at low speed. (EMEA and APAC Only).
• The vehicle stalls at low speeds and/or coming to a stop This bulletin involves reprogramming the PCM with the latest available software.
Reported code forms
Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
Jeep
P0420Catalyst System Efficiency Below Threshold Bank 1Jeep
P0430Catalyst System Efficiency Below Threshold Bank 2Jeep
P0456EVAP System Small LeakCheck vehicle applicability
A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Jeep | WRANGLER | 2019 |