What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P20EESCR NOX Catalyst Efficiency Below Threshold - Bank 1P20EE-00SCR Nox Catalyst Efficiency Below Threshold - Bank 1 Catalyst 1P20EENOx Catalyst Efficiency Below ThresholdP20EESCR NOx CATALYST EFFICIENCY BELOW THRESHOLD - BANK 1View all · Manufacturer wording →
Manufacturer communications
17Original wording in English
RAM
Reported code forms P20EE-00
Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes…
RAM
Reported code forms P20EE-00
NOte: Revision is being created to correct the Models affected. Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set…
RAM
Reported code forms P20EE-00
Flash: Powertrain Control Module (PCM) Updates V2C 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):…
RAM
Reported code forms P20EE - 00
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):**…
RAM
Reported code forms P20EE
Powertrain Contol Module Over The Air Update to V2B (Diesel Only) Software Version (FOTA) 2025 - 2026 (DJ) RAM 2500 Pickup 2025 - 2026 (D2) RAM 3500 Pickup 2025 - 2026 (DD) RAM 3500 Cab Chassis 2025 - 2026 (DF) RAM 3500…
RAM
Reported code forms P20EE
Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the PCM with the latest available software. There will be a choice between two calibrations. One for vehicles that utilize an ammonia…
Check vehicle applicability
6A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.