Isuzu 2000 Trooper Workshop Manual page 1003

6E–134
TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
D Poor connection at PCM-Inspect harness connectors
for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.
D Damaged harness- Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
Mass Air Flow (MAF) display on the Tech 2 while
moving connectors and wiring harnesses related to the
sensor.
D Plugged intake air duct or filter element
D A wide–open throttle acceleration from a stop should
cause the mass air flow displayed on a Tech 2 to
increase from about 3–6 g/s at idle to 100 g/s or greater
at the time of the 1–2 shift. If not, check for a restriction.
Step
1 Was the "On-Board Diagnostic (OBD) System Check"
performed?
2 1. Ignition "OFF."
2. Disconnect the Mass Air Flow (MAF) Sensor
harness connector from the MAF Sensor.
3. Place an unpowered test lamp between the 12 volt
signal circuit and the ground circuit, both at the MAF
Sensor connector.
4. Ignition "ON," Engine"OFF."
Did the test lamp illuminate?
3 1. Ignition "ON," Engine "OFF."
2. Using a Digital Voltmeter (DVM), check the 12 volt
signal circuit for the correct voltage.
Did the DVM indicate a value within the following
range?
4 1. Ignition "OFF."
2. Check the 12 volt signal circuit for the following
conditions:
D
An open circuit
D
A short to ground
Was the problem found?
5 Check the MAF ground circuit for the following
conditions:
D
An open circuit
D
A short to voltage
Was a problem found?
6 1. Ignition "OFF."
2. Check the MAF Sensor signal circuit between the
PCM and the MAF Sensor for the following
conditions:
D
An open circuit
D
A short to ground
D
A short to battery voltage
Was a problem found?
DTC P0101 – MAF System Performance
Action
A change in the display will indicate the location of
the fault.
If DTC P0101 cannot be duplicated, the
information included in the Faillure Records data
can be useful in determined vehicle mileage since
the DTC was last set.
If it is determined that the DTC occurs
intermittently, performing the DTC P001
Diagnostic Chart may isolate the cause of the
fault.
Value(s) Yes
— Go to Step 2
— Go to Step 6
11.5 to 12.5
Go to Step 5
Volt
— Verify repair
— Verify repair
— Verify repair
No
Go to OBD
System
Check
Go to Step 3
Go to Step 4
—
—
Go to Step 7