P0102
Read the instructions below then
start the fault diagnostic procedure.
Symptom: CHECK ENGINE goes on after two driving cycles.
Engine speed drops slower than normal when accelerator pedal is released.
Misfiring can occur before trouble code is generated.
Mass Air Flow Circuit. Low Input.
Fault symptoms
|
•
|
CHECK ENGINE goes on after two driving cycles.
|
|
•
|
Engine speed drops slower than normal when accelerator pedal is released.
|
|
•
|
Misfiring can occur before trouble code is generated.
|
On-Board Diagnostics
Type of diagnosis:
|
-
|
Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.
|
Enable criteria:
|
-
|
Crankshaft rotating. Main relay voltage above 10V.
|
Fault criteria:
|
-
|
Frequency lower than 500 Hz for more than 0.5 s.
|
Dependents:
System reaction to a fault:
|
-
|
Fuel adaptation reset. Intake pressure and intake air temperature used as substitute values.
|
OK report:
|
-
|
60 s has past since start. Fault criteria for P0100, P0102 or P0103 not fulfilled.
|
|
-
|
Conditions for multiplicative fuel adaptation fulfilled. Mass air flow sensor value corresponds with both the air mass flow calculated from intake manifold pressure and the air mass flow calculated from throttle position.
|
Fault handling:
(For more information, see
.)
Diagnostic help
The mass air flow sensor is sending pulses to the control module but the frequency is too low. Consequently, the sensor is powered and is in contact with the control module input.
In most cases, the trouble code indicates an internal fault in the sensor but a major leak between the sensor and the throttle, i.e. a disconnected sensor, can also generate it.
Functions in the diagnostic tool related to the fault are:
|
•
|
Diagnostic status for the diagnosis.
|
|
•
|
Mass air flow sensor value, unit g/s.
|
|
•
|
Air mass deviation from calculated, unit %.
|
For more information, see
.
Checking the wiring
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Observe the multimeter, diagnostic tool or test lamp during the check.
