Fault Information

Fault Code Description
The measured air mass is too high compared with the calculated air mass.

Fault Code Conditions
General Conditions	Monitoring runs continuously with active exhaust-gas recirculation control in the following time grid: 20 ms. Control unit voltage: 9.5 V to 16 V.
Terminal Condition
Driving Conditions

Fault Time Condition
The fault is entered if it is present for longer than the following period (debounce time): 5000 ms

Service Plan
Check the following possible fault causes: 1. Air cleaner faulty. Note: As of September 2011, air filter elements with increased tolerances were installed for N57D30O1 and N57D30T1, this can make the measured air mass appear too high, which leads to this fault. The faulty air filter elements have a thick grey fleece. These air filter elements must be replaced by a new filter element (thin white fleece). 2. Leaking bypass pipe of EGR cooler (pipe could be broken). 3. Exhaust gas recirculation cooler clogged. 4. Charge-air temperature sensor faulty (displays values that are too high, mostly without fault entry). 5. Exhaust gas pressure sensor before turbine faulty (in conjunction with the fault codes 27B900 and/or 4C83 and/or 28DE00 and/or 4990). 6. Charge pressure sensor faulty. 7. Leaks in the air mass system: After the compressor (in conjunction with faults 241200 or 4674 and/or 241300 or 4679). The fault can also occur in combination with charging pressure control deviations. Such combinations are a sign that leaks in the air mass system after the compressor are the cause. Oil patches are signs of leaks. Check whether sealing rings on charge air hoses are rolled back or missing! 8. Exhaust-gas recirculation valve jams in closed position (in conjunction with the faults 272E00 or 4C9E and/or 255B00 or 40D4) or does not close correctly.

Service Plan

Check the following possible fault causes:
1. Air cleaner faulty.
Note: As of September 2011, air filter elements with increased tolerances were installed for N57D30O1 and N57D30T1, this can make the measured air mass appear too high, which leads to this fault. The faulty air filter elements have a thick grey fleece. These air filter elements must be replaced by a new filter element (thin white fleece).
2. Leaking bypass pipe of EGR cooler (pipe could be broken).
3. Exhaust gas recirculation cooler clogged.
4. Charge-air temperature sensor faulty (displays values that are too high, mostly without fault entry).
5. Exhaust gas pressure sensor before turbine faulty (in conjunction with the fault codes 27B900 and/or 4C83 and/or 28DE00 and/or 4990).
6. Charge pressure sensor faulty.
7. Leaks in the air mass system:
After the compressor (in conjunction with faults 241200 or 4674 and/or 241300 or 4679).
The fault can also occur in combination with charging pressure control deviations. Such combinations are a sign that leaks in the air mass system after the compressor are the cause.
Oil patches are signs of leaks.
Check whether sealing rings on charge air hoses are rolled back or missing!
8. Exhaust-gas recirculation valve jams in closed position (in conjunction with the faults 272E00 or 4C9E and/or 255B00 or 40D4) or does not close correctly.

Fault Impact
The fault can cause high fuel consumption and jerking.

Warnings
Warning Lights	None
Control Center Messages

Service Notes
- Check the sensor system for faults. Here, check in particular the charge-air temperature sensor on the display for plausible values. During a certain period, sensors were installed that displayed excessively high temperatures. - Check the occurrence of the fault with other faults. If leaks were found in the exhaust emission system, the following service function must be carried out: Delete adaptations, exhaust emission system. If leaks were found in the air mass system, the following service function must be carried out: Delete adaptations, air mass system. If the exhaust-gas recirculation valve is being renewed, the following service function must be carried out: Delete adaptations, air mass system.

Service Notes

- Check the sensor system for faults. Here, check in particular the charge-air temperature sensor on the display for plausible values. During a certain period, sensors were installed that displayed excessively high temperatures.
- Check the occurrence of the fault with other faults.
If leaks were found in the exhaust emission system, the following service function must be carried out: Delete adaptations, exhaust emission system.
If leaks were found in the air mass system, the following service function must be carried out: Delete adaptations, air mass system.
If the exhaust-gas recirculation valve is being renewed, the following service function must be carried out: Delete adaptations, air mass system.