P0100
Read the instructions below then
start the fault diagnostic procedure.
Symptom: CHECK ENGINE lamp goes on after two driving cycles.
Engine speed drops slower than normal when accelerator pedal released.
Possible misfiring before diagnostic trouble code is generated.
Mass Air Flow Circuit. No Signal.
Fault symptoms
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CHECK ENGINE lamp goes on after two driving cycles.
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Engine speed drops slower than normal when accelerator pedal released.
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Possible misfiring before diagnostic trouble code is generated.
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On-Board Diagnostics
Type of diagnosis:
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Continuous. However, it is interrupted once the fault criteria have been fulfilled and does not restart until the next driving cycle.
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Enable criteria:
(Conditions that must be fulfilled for diagnostics to be performed.)
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Crankshaft rotating. Main relay voltage above 10V.
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Fault criteria:
(When enable criteria have been fulfilled, diagnostics will check if the fault criteria have been fulfilled.)
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No frequency for more than 0.5 s.
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Dependents:
(Once fault criteria have been fulfilled, a number of other diagnostics must report OK before the diagnostic trouble code can finally be generated.)
System reaction to a fault:
(Once the fault criteria have been fulfilled, certain measures will sometimes be taken.)
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Fuel adaptation will be zeroed. Intake pressure and intake air temperature are used as substitute values.
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OK report:
(This diagnosis may be included as a dependent to another diagnosis and must therefore report OK even if it is continuous. The OK report is also used in fault handling to count down the fault counter.)
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60 s. has passed since start. Fault criteria not fulfilled for P0100, P0102 or P0103.
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Conditions for multiplicative fuel adaptation fulfilled. The value from the mass air flow sensor corresponds with the mass air flow calculated both from the intake manifold pressure and from the throttle position.
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Fault handling:
(Refer to section “Fault diagnosis, general” for more information.)
Diagnostic help
Fault diagnosis concerns an electrical fault in the connecting leads or in the sensor.
Diagnostic tool functions related to the fault are:
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Diagnostic status for the diagnosis.
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Mass air flow sensor reading, unit g/s.
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Air mass deviation from calculated, unit %
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Refer also to the description of readings under ”Fault diagnosis, general” for more information
Check the wiring
Jiggle the wiring harness at several points and in different directions to check if there are intermittent breaks and short-circuits in the leads. Observe the multimeter, test lamp or diagnostic instrument during the test.
