T8 / P0101 00
Read the instructions below then
start the fault diagnostic procedure.
Symptom: Fault indicator lamp (for further information see WIS Fault diagnosis, general)
Cruise control not working.
Limp home
Possible driveability problem.
Mass air flow sensor malfunction (variation from calculated air mass)
Fault symptom
Fault indicator lamp (for further information see WIS Fault diagnosis, general)
Cruise control not working.
Limp home
Possible driveability problem.
On-board diagnosis
Type of diagnosis:
Enable criteria:
| Battery voltage must be between 11 - 16 V. |
| Vehicle speed above 30 km/h for more than 60 s accumulated time. |
| Coolant temperature between 71°C and 115°C. |
| Engine speed between 1400 and 4000 rpm. |
Fault criteria:
| Conditions for test 1, 2, 3 or 4 are fulfilled. |
| • | The mass air flow sensor shows a value 12% lower than the calculated one while multiplicative adaptation is greater than 17%. |
| • | The mass air flow sensor shows a value 12% higher than the calculated one while multiplicative adaptation is less than -17%. |
| • | The mass air flow sensor shows a value 30% lower than the calculated one. |
| • | The mass air flow sensor shows a value 30% higher than the calculated one. |
Dependent:
System reaction to a fault:
| The system continues to function with a calculated air mass instead of the value from the mass air flow sensor. |
| Boost pressure adaption is blocked and reset. |
| Limited acceleration and idle function. |
| Secondary air pump not active, if fitted. |
OK report:
| Diagnosis completed without fault report. |
Fault handling:
| (See section Fault handling III, "Other emission-related components and functions" for more information.) |
Checking the wiring harness
Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.
Diagnostic help
Diagnosis regards:
| The DTC indicates that the value from the mass air flow sensor has been deemed unreliable after comparison with a calculated value. This could be due to an air leak or a faulty mass air flow sensor. |
| The air mass signal is compared to a calculated value under light, normal and continuous engine loads. The calculated value is derived from the pressures given by the pressure sensors in the intake system. |
| First check the integrity of the intake system. Then continue with fault diagnosis. |
| If DTC P0171 or P0172 is stored, it is cleared by P0101. |
Functions in the diagnostic tool related to the fault:
| • | Airmass / Combustion Calculated |
| (See also description of readings/activations in diagnostic tool) |
