Freightliner Sprinter 1500 2019–2021 — technical service bulletin
Bulletin LI49.20-N-079593 · NHTSA communication 11021173 · issued Jul 25, 2025
Technical service bulletin
communication type
Unknown / Other
component
2019–2021
model years
12
vehicle entries
Official summary
Check engine light with fault code P20EEFE in the CDI control unit CDI (N3/47) Complaint Check engine light is illuminated with fault code P20EEFE "The efficiency of component 'SCR catalytic converter' is not sufficient" stored in the CDI control unit (N3/47). Cause Excessive ammonia slip is being detected in the SCR system, often triggered by IUMPR (In-Use Monitor Performance Ratio) thresholds. This typically indicates that the SCR catalyst is not converting DEF (AdBlue) efficiently under moni- tored conditions. Common Driving Scenario: •Non-dynamic driving (e.g., highway cruising with cruise
Vehicles covered
- 2021 Freightliner Sprinter 1500
- 2021 Freightliner Sprinter 2500
- 2021 Freightliner Sprinter 3500
- 2021 Freightliner Sprinter 4500
- 2019 Freightliner Sprinter (VS30)
- 2020 Freightliner Sprinter (VS30)
- 2021 Mercedes-Benz Sprinter 1500
- 2021 Mercedes-Benz Sprinter 2500
- 2021 Mercedes-Benz Sprinter 3500
- 2021 Mercedes-Benz Sprinter 4500
- 2019 Mercedes-Benz Sprinter (VS30)
- 2020 Mercedes-Benz Sprinter (VS30)
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.