Service bulletin LI49.20-N-076565
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.
| Type | Service bulletin |
|---|---|
| NHTSA id | 11021170 |
| Published by NHTSA | 2025-08-01 |
| Manufacturer's number | LI49.20-N-076565 |
| Manufacturer's date | 2025-07-23 |
| NHTSA component | UNKNOWN OR OTHER |
NHTSA's 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):
The document
The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.
Trouble codes named
P300E
| FREIGHTLINER SPRINTER (VS30) | 2019, 2020 (the catalog's model; the bulletin names a series or trim of it) |
|---|---|
| FREIGHTLINER SPRINTER 1500 | 2021 (the catalog's model; the bulletin names a series or trim of it) |
| FREIGHTLINER SPRINTER 2500 | 2021 (the catalog's model; the bulletin names a series or trim of it) |
| FREIGHTLINER SPRINTER 3500 | 2021 (the catalog's model; the bulletin names a series or trim of it) |
| FREIGHTLINER SPRINTER 4500 | 2021 (the catalog's model; the bulletin names a series or trim of it) |
| MERCEDES-BENZ SPRINTER (VS30) | 2019, 2020 (the catalog's model; the bulletin names a series or trim of it) |
| MERCEDES-BENZ SPRINTER 1500 | 2021 (the catalog's model; the bulletin names a series or trim of it) |
| MERCEDES-BENZ SPRINTER 2500 | 2021 (the catalog's model; the bulletin names a series or trim of it) |
| MERCEDES-BENZ SPRINTER 3500 | 2021 (the catalog's model; the bulletin names a series or trim of it) |
| MERCEDES-BENZ SPRINTER 4500 | 2021 (the catalog's model; the bulletin names a series or trim of it) |
Listing a model year does not mean every vehicle of it is concerned: the document says which.