P1073
P1073Diagnosis information - Control unit DME (DFI)
Mass airflow range near idle speed, implausible too low
Diagnostic conditions
- Idle speed > 2 Minute(s)
- Trip with different operating conditions
- none of the following faults stored: Intake manifold pressure sensor, Throttle adjusting unit, Ambient pressure sensor, Intake air temperature sensor, Speed sensor, Valve lift control, Camshaft adjustment, Intake pipe switchover
Possible fault causes
- Oil filler cap was opened while engine was running
(e.g. to top up oil)
(See Environmental condition 6 for first fault occurrence >SE10 Engine compartment lid open<)
- Throttle valve adaptation performed while boundary conditions are violated.
(See (INFORMATION 2)
- Throttle adjusting unit soiled
- Exhaust system Blocked / Cross section Narrowed
- Intake manifold pressure sensor- Electrical plug connection loose, oxidized, corroded, interrupted
- Tank vent Faulty - Closed (mechanical / electric)
- Fault in area Intake manifold pressure sensor, Throttle adjusting unit, Ambient pressure sensor, Intake air temperature sensor, Speed sensor, Valve lift control, Camshaft adjustment, Intake pipe switchover
Fault setting condition(s)
- Impermissibly large deviation of the measured air mass from the calculated air mass. (See INFORMATION 1)
INFORMATION
1. In this diagnosis, the intake system between the throttle valve and the engine (intake valves) is monitored.
- A mass air flow is calculated from the signals from the throttle potentiometer, engine speed sensor, intake air temperature sensor and ambient pressure sensor as well as other engine operating values.
- The calculated mass airflow is compared with that measured by the pressure sensor.
- A deviation may be due to both the calculated mass airflow and the measured mass airflow.
2. A note to this effect is stored in the environmental data for the fault entry value > XX-Status Of throttle adaptation conditions<.
- The value indicates whether the throttle valve was taught under violated boundary conditions.
- 0 ... 127 = Throttle valve was taught under the correct boundary conditions.
- 128 ... 255 = Throttle valve was taught under violated boundary conditions.