Isuzu 2000 Trooper Workshop Manual page 1008

Diagnostic Trouble Code (DTC) P0103 MAF Sensor Circuit High Frequency
Circuit Description
The mass air flow (MAF) sensor measures the amount of
air which passes through it into the engine during a given
time. The powertrain control module (PCM) uses the
mass air flow information to monitor engine operating
conditions for fuel delivery calculations. A large quantity
of air entering the engine indicates an acceleration or high
load situation, while a small quantity of air indicates
deceleration or idle.
The MAF sensor produces a frequency signal which can
be monitored using a Tech 2. The frequency will vary
within a range of around 4 to 7g/s at idle to around 25 to 40
g/s at maximum engine load. DTC P0103 will be set if the
signal from the MAF sensor is above the possible range of
a normally operating MAF sensor.
Conditions for Setting the DTC
D The engine is running above 500 RPM for more than
10 seconds.
D System voltage is above 11.5 volts.
D MAF signal frequency is above 40g/s for a total of 50
percent of the last 200 samples monitored. A sample
is taken every cylinder event.
TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Action Taken When the DTC Sets
D The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
D The PCM calculates an airflow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.
D The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for clearing the MIL/DTC
D The PCM will turn the MIL "OFF" on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.
D A history DTC P0103 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
D DTC P0103 can be cleared by using the Tech 2 "Clear
Info" function or by disconnecting the PCM battery
feed.
Diagnostic Aids
If DTC P0103 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
6E–139
D06RY00164