Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 838

6E–81

3.2L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0101 – MAF System Performance

  (Cont'd)

Step

No

Yes

Value(s)

Action

4

1. Ignition “OFF.”
2. Disconnect the MAF sensor connector.
3. Ignition “ON,” engine “OFF.”
4. Using DVM 5-8840-0285-0, measure voltage

between the MAF sensor signal circuit and chassis
ground.

Is the voltage near the specified value?

5 V

Go to 

Step 5

Go to

 Step 6

5

Connect a test light (5-8840-0607-0) between the MAF
sensor ignition feed and ground circuits at the MAF
sensor harness connector.

Is the test light “ON?”

—

Go to 

Step 9

Go to

 Step 8

6

Is the voltage less than the specified value?

4.5 V

Go to 

Step 14

Go to

 Step 7

7

1. Ignition “OFF,” disconnect the ECM.
2. Ignition “ON,” engine “OFF.”
3. Measure voltage between the MAF signal circuit

and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 20

Go to

 Step 17

8

Connect a test light (5-8840-0607-0) between the MAF
sensor ignition feed circuit and chassis ground.

Is the test light “ON?”

—

Go to 

Step 9

Go to

 Step 10

9

1. Check for a poor connection at the MAF sensor.
2. If a poor connection is found, replace faulty

terminal(s).

Was a poor connection found?

—

Verify repair

Go to

 Step 10

10

1. Check the MAF sensor damage.
2. If the MAF sensor damage is found, replace the

MAF sensor.

Was the MAF sensor damage found?

—

Verify repair

Go to

 Step 11

11

Replace the ECM.

Is the action complete?

—

Verify repair

—

6E–82

3.2L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0102 (Flash DTC=61) MAF Sensor Circuit

Low Frequency

060RW077

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 Engine Control Module ECM 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 7 g/s at idle to around 25 to 40
g/s at maximum engine load.  DTC P0102 will be set if the
signal from the MAF sensor is below the possible range of
a normally operating MAF sensor.

Conditions for Setting the DTC

D

The engine is running between 500 and 2000 RPM for
greater than 2 seconds.

D

System voltage is under 300m volts.

Action Taken When the DTC Sets

D

The ECM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

D

The ECM calculates an air flow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.

D

The ECM 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 ECM 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 P0102 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

D

DTC P0102 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the ECM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at ECM – Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

D

Misrouted harness – Inspect the MAF sensor harness
to ensure that it is not routed too close to high voltage
wires.

D

Damaged harness – Inspect the wiring harness for
damage.  If the harness appears to be OK, observe the
Tech 2 while moving connectors and wiring harnesses
related to the MAF sensor.  A change in the display will
indicate the location of the fault.

6E–83

3.2L ENGINE DRIVEABILITY AND EMISSIONS

D

Plugged intake air duct or filter element – 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/second at idle to 100 g/second or greater
at the time of the 1-2 shift.  If not, check for a restriction.

If DTC P0102 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. This step verifies that the problem is present at idle.

4. A voltage reading of less than 4 or over 5 volts at the

MAF sensor signal circuit indicates a fault in the
wiring or a poor connection.

5. This verifies that ignition feed voltage and a good

ground are available at the MAF sensor.

DTC P0102 – MAF Sensor Circuit  Low Frequency

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

1. Start the engine.
2. With the engine idling, monitor “MAF Frequency”

display on the Tech 2.

Is the “MAF Frequency” below the specified value?

4 

∼

 7 g/s

Go to 

Step 4

Go to 

Step 5

3

1. Ignition “ON,” engine “OFF.”
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “Specific DTC” info for DTC

P0102.

Does the Tech 2 indicate DTC P0102 failed this
ignition?

—

Go to 

Step 4

Refer to

Diagnostic

Aids

4

1. Ignition “OFF.”
2. Disconnect the MAF sensor connector.
3. Ignition “ON,” engine “OFF.”
4. Using a DVM, measure voltage between the MAF

sensor signal circuit and battery ground.

Is the voltage near the specified value?

5 V

Go to 

Step 5

Go to 

Step 8

5

Connect a test light between the MAF sensor ignition
feed and ground circuits at the MAF sensor harness
connector.

Is the test light “ON?”

—

Go to 

Step 13

Go to 

Step 6

6

Connect a test light between the MAF sensor ignition
feed circuit and battery ground.

Is the test light “ON?”

—

Go to 

Step 12

Go to 

Step 7

7

1. Check for a poor connection at the MAF sensor.
2. If a poor connection is found, replace the faulty

terminal(s).

Was a poor connection found?

—

Verify repair

Go to 

Step 11

6E–84

3.2L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0102 – MAF Sensor Circuit  Low Frequency

  (Cont'd)

Step

No

Yes

Value(s)

Action

8

1. Ignition “OFF.”
2. Disconnect the MAF sensor.
3. Disconnect the ECM connector for the MAF signal

circuit.

4. Ignition “ON,” engine “OFF.”
5. With the DVM, measure the voltage between the

MAF signal terminal at the ECM and battery ground.

Is the voltage under the specified value?

4 V

Go to 

Step 9

Go to 

Step 10

9

1. Ignition “OFF.”
2. Disconnect the ECM white connector.
3. Ignition “ON.”
4. Check the MAF sensor signal circuit for a short to 5

volts.

Is the action complete?

—

Verify repair

—

10

1. Ignition “OFF.”
2. Disconnect the ECM white connector.
3. Ignition “ON.”
4. Check the MAF sensor signal circuit between the

ECM and the MAF sensor for an open, short to
ground, or short to the MAF ground circuit.

Is the action complete?

—

Verify repair

Go to 

Step 13

11

Locate and repair the open in the ground circuit to the
MAF sensor.

Is the action complete?

—

Verify repair

—

12

Locate and repair the open in the ignition feed circuit to
the MAF sensor.

Is the action complete?

—

Verify repair

—

13

Replace the MAF sensor.

Is the action complete?

—

Verify repair

Go to 

Step 14

14

Replace the ECM.

Is the action complete?

—

Verify repair

—