RAM
18-002-26
Manufacturer communications
- Publication date
- 2026-01-16
- Received by NHTSA
- 2026-01-21
- NHTSA record numbers
- 11027730
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. Customers may also experience the following:
• Catalyst damage and restricted exhaust flow, resulting in a reduction of engine power. 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. Customers may also experience the following:
• Catalyst damage and restricted exhaust flow, resulting in a reduction of engine power. 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.
Ram
P0420Catalyst System Efficiency Below Threshold Bank 1Ram
P0430Catalyst System Efficiency Below Threshold Bank 2Check vehicle applicability
A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.