P300E · Manufacturer communications

FREIGHTLINER, MERCEDES-BENZ · 2026-01-14

Complaint The check engine light is on, with a possibility in a reduction of power, with no soot present in the exhaust system. Fault codes: P300E5F The fill level of the diesel particulate filter is too high. (Early warning) P300E5E The fill level of the diesel particulate filter is too high. Regeneration of the diesel particulate filter is disabled. Additional information: No additional fault codes related to the Diesel Particulate Filter (DPF) system or the Exhaust Gas Recirculation (EGR) system may be present for this LI to apply. Cause These fault codes may be triggered due to unfavorable driving conditions, such as: •Frequent short-distance trips •Extended idle periods •Infrequent highway driving •Incomplete regeneration cycles These conditions can lead to excessive soot…

FREIGHTLINER, MERCEDES-BENZ · 2025-07-23

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…

FREIGHTLINER, MERCEDES-BENZ · 2025-06-16

Check engine light with fault code P300E55 with H12 Complaint The check engine light is activated, accompanied by the following fault code related to the Exhaust gas recirculation cooler (low pressure): •P300E55 The efficiency of component 'Exhaust gas recirculation cooler (low pressure)' is not sufficient. Cause The issue is attributed to an error in the coding of the climate control unit software (HVAC177). Remedy Software Update Instructions Please proceed as follows for the different variants:

FREIGHTLINER, MERCEDES-BENZ · 2025-05-19

Complaint The check engine light is activated, accompanied by the following fault code related to the Exhaust gas recirculation cooler (low pressure): •P300E55 The efficiency of component 'Exhaust gas recirculation cooler (low pressure)' is not sufficient. Cause The issue is attributed to an error in the coding of the climate control unit software (HVAC177). Remedy A software update to correct the coding error is currently in the process of release for the Aftersales network. In the interim, please proceed as follows: •Erase the fault memory (DTCs) from the control unit. •Return the vehicle to the customer. •No further diagnostic or repair procedures are required at this time.

FREIGHTLINER, MERCEDES-BENZ · 2024-10-17

Complaint: Check engine light with fault code: P300E3B the efficiency of component 'SCR catalytic converter' is not sufficient, is present in the CDI control unit CDI (N3/28). Cause: This subject is currently being analyzed for all 907s equipped with the OM642 engine. Follow the instructions related to this subject to collect information about your vehicle. After completing the checks, please open a TIPS case and at-tach the collected information.

FREIGHTLINER, MERCEDES-BENZ · 2024-09-25

Complaint Check engine light with fault code: P300E3B the efficiency of component 'SCR catalytic converter' is not sufficient, is present in the CDI control unit CDI (N3/28). Cause This subject is currently being analyzed for all 907s equipped with the OM642 engine. Follow the instructions related to this subject to collect information about your vehicle. After completing the checks, please open a TIPS case and attach the collected information. Remedy Please complete the following inspections and tests: 1. Perform a tailpipe wipe test and document the results along with photographs. 2. Inspect the NOx connectors, pins, crimps, and harnesses between N37/7 and N37/8 to F152f59, Z7108, W105/3, and X30/81. 3. Provide actual values/sensor plausibility test results for all pressure and…