P1072

P1072

Diagnosis information - Control unit DME (DFI)

Mass air flow range near idle speed, implausible too high

Diagnostic conditions
- Idle speed more than 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])
- Oil filler cap leaks
- Throttle valve adaptation performed while boundary conditions are violated.
(See [Information] 3)
- Positive crankcase ventilation hose leaks
(See [Information] 1)
- Intake system leaks - between Throttle valve and Engine (Intake valve)
- Tank vent Faulty - open
- Intake manifold pressure sensor - Electrical plug connection loose, oxidized, corroded, interrupted
- 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] 2)

INFORMATION:
1. The following components are NOT tested during an overpressure test of the intake duct:
- Check valve for ventilation (Suction hose Turbocharger) --> See Installation position [A]
- Check valve for ventilation (Intake distributor) --> See Installation position [B]
- Positive crankcase ventilation hose between Check valve for ventilation and Crankcase --> See Installation position [C]
- Crankcase

2. 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 air flow is compared with that measured by the pressure sensor.
- A deviation may be due to both the calculated mass air flow and the measured mass air flow.

3. A note to this effect is stored in the environmental data for the fault entry value [XX-Status of throttle valve adaptation conditions 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.