{"nhtsa_id":11021170,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2025-08-01","date":"2025-07-23","document_id":"LI49.20-N-076565","mfr_campaign":null,"replaces":null,"component":"UNKNOWN OR OTHER","mfr_system":null,"summary":"Check engine light with fault code P300E3B in the CDI control unit CDI (N3/28) Complaint Check engine light is illuminated with fault code P300E3B “The efficiency of component 'SCR catalytic converter' is not sufficient\" stored in the CDI control unit (N3/28). 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 control set) •Minimal load changes, steady-state exhaust flow Contributing Factors: •Software influence – IUMPR (In-Use Monitor Performance Ratio) thresholds •DEF Overdosing – Over-injection due to faulty NOx sensors, dosing valve issues, or poor DEF quality •Low Exhaust or Catalyst Temperatures – Common under low-load conditions; reduces SCR conversion efficiency •Catalyst Degradation or Contamination – Aging catalyst or contamination from oil, coolant, or poor-quality DEF Remedy IMPORTANT: Do not replace any components unless instructed through TIPS. For Model Year 2019–2021 Vehicles: •Update the following control units to the latest available software: N3/28 – Motor Electronics 'CDI61NFZ' for combustion engine 'OM642' (CDI):","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11021170-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11021170-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11021170","components":[],"codes":["P300E"],"topics":[],"vehicles":[{"make":"FREIGHTLINER","model":"SPRINTER (VS30)","year_from":2019,"year_to":2020,"match":"base","vehicle_ids":["2019_freightliner_sprinter","2020_freightliner_sprinter"]},{"make":"FREIGHTLINER","model":"SPRINTER 1500","year_from":2021,"year_to":2021,"match":"base","vehicle_ids":["2021_freightliner_sprinter"]},{"make":"FREIGHTLINER","model":"SPRINTER 2500","year_from":2021,"year_to":2021,"match":"base","vehicle_ids":["2021_freightliner_sprinter"]},{"make":"FREIGHTLINER","model":"SPRINTER 3500","year_from":2021,"year_to":2021,"match":"base","vehicle_ids":["2021_freightliner_sprinter"]},{"make":"FREIGHTLINER","model":"SPRINTER 4500","year_from":2021,"year_to":2021,"match":"base","vehicle_ids":["2021_freightliner_sprinter"]},{"make":"MERCEDES-BENZ","model":"SPRINTER (VS30)","year_from":2019,"year_to":2020,"match":"base","vehicle_ids":["2019_mercedes-benz_sprinter","2020_mercedes-benz_sprinter"]},{"make":"MERCEDES-BENZ","model":"SPRINTER 1500","year_from":2021,"year_to":2021,"match":"base","vehicle_ids":["2021_mercedes-benz_sprinter"]},{"make":"MERCEDES-BENZ","model":"SPRINTER 2500","year_from":2021,"year_to":2021,"match":"base","vehicle_ids":["2021_mercedes-benz_sprinter"]},{"make":"MERCEDES-BENZ","model":"SPRINTER 3500","year_from":2021,"year_to":2021,"match":"base","vehicle_ids":["2021_mercedes-benz_sprinter"]},{"make":"MERCEDES-BENZ","model":"SPRINTER 4500","year_from":2021,"year_to":2021,"match":"base","vehicle_ids":["2021_mercedes-benz_sprinter"]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}