Mass Airflow Sensor ( T126 )
Make sure that the mass air flow sensor is installed correctly Check the connectors and electrical wiring. Replace the mass air flow sensor Note Always perform a reset of adaption values of the mass air flow sensor if the mass air flow sensor is replaced, or if a leak in the engine intake system have been fixed For EUV engines: If the operating time with the error code active is more than 10 hours, the EGR cooler should be drained because it is likely that the condensation has formed in the air-cooled EGR cooler when the EGR system has been turned off. Perform emptying according to the instructions in the Service Manual, section 01-65. To verify that the fault is fixed, carry out a free acceleration and check that the MAF signal moves
What you'll see
No driver-visible symptom recorded.
System reaction
The ECU shuts off the EGR system Engine performance is reduced It may not possible to erase an active fault code, depending on the emissions class of the vehicle
Diagnostic depth
The value from the mass flow sensor is constant although the engine operation/speed indicates that it should vary
Faulty mass airflow sensor ( T126)