Nissan Pathfinder (2005 year). Manual - part 167

DTC P0101 MAF SENSOR

EC-187

2005 Pathfinder

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

Diagnostic Procedure

UBS00K5F

INSPECTION START

Which malfunction (A or B) is duplicated?

A or B

>> GO TO 3.

>> GO TO 2.

CHECK INTAKE SYSTEM

Check the following for connection.

●

Air duct

●

Vacuum hoses

●

Intake air passage between air duct and intake manifold

OK or NG

>> GO TO 3.

>> Reconnect the parts.

TER-

MINAL

NO.

WIRE

COLOR

ITEM

CONDITION

DATA (DC Voltage)

Mass air flow sensor

[Engine is running]

●

Warm-up condition

●

Idle speed

0.9 - 1.2V

[Engine is running]

●

Warm-up condition

●

Engine speed is 2,500 rpm

1.5 - 1.8V

Sensor ground

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 0V

111

ECM relay
(Self shut-off)

[Engine is running]
[Ignition switch: OFF]

●

For a few seconds after turning ignition
switch OFF

0 - 1.5V

[Ignition switch: OFF]

●

More than a few seconds after turning igni-
tion switch OFF

BATTERY VOLTAGE
(11 - 14V)

119

120

R
P

Power supply for ECM

[Ignition switch: ON]

BATTERY VOLTAGE
(11 - 14V)

EC-188

DTC P0101 MAF SENSOR

2005 Pathfinder

CHECK GROUND CONNECTIONS

Turn ignition switch OFF.

Loosen and retighten three ground screws on the body. Refer to

EC-165, "Ground Inspection"

OK or NG

>> GO TO 4.

>> Repair or replace ground connections.

CHECK MAF SENSOR POWER SUPPLY CIRCUIT

Disconnect mass air flow (MAF) sensor harness connector.

Turn ignition switch ON.

Check voltage between MAF sensor terminal 2 and ground with
CONSULT-II or tester.

OK or NG

>> GO TO 6.

>> GO TO 5.

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E2, F32

●

Harness for open or short between IPDM E/R and mass air flow sensor

●

Harness for open or short between mass air flow sensor and ECM

>> Repair harness or connectors.

BBIA0539E

BBIA0541E

Voltage: Battery voltage

PBIB1168E

DTC P0101 MAF SENSOR

EC-189

2005 Pathfinder

CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

Turn ignition switch OFF.

Disconnect ECM harness connector.

Check harness continuity between MAF sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.

Also check harness for short to ground and short to power.

OK or NG

>> GO TO 7.

>> Repair open circuit or short to ground or short to power in harness or connectors.

CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

Check harness continuity between MAF sensor terminal 4 and ECM terminal 51.
Refer to Wiring Diagram.

Also check harness for short to ground and short to power.

OK or NG

>> GO TO 8.

>> Repair open circuit or short to ground or short to power in harness or connectors.

CHECK INTAKE AIR TEMPERATURE SENSOR

Refer to

EC-203, "Component Inspection"

OK or NG

>> GO TO 9.

>> Replace intake air temperature sensor.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Refer to

EC-348, "Component Inspection"

OK or NG

>> GO TO 10.

>> Replace EVAP control system pressure sensor.

10.

CHECK MASS AIR FLOW SENSOR

Refer to

EC-189, "Component Inspection"

OK or NG

>> GO TO 11.

>> Replace mass air flow sensor.

11.

CHECK INTERMITTENT INCIDENT

Refer to

EC-158, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

>> INSPECTION END

Component Inspection

UBS00K5G

MASS AIR FLOW SENSOR

With CONSULT-II

Reconnect all harness connectors disconnected.

Start engine and warm it up to normal operating temperature.

Connect CONSULT-II and select “DATA MONITOR” mode.

Continuity should exist.

EC-190

DTC P0101 MAF SENSOR

2005 Pathfinder

Select “MAS A/F SE-B1” and check indication under the follow-
ing conditions.

*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.

If the voltage is out of specification, proceed the following.

Check for the cause of uneven air flow through mass air flow sensor. Refer to following.

●

Crushed air ducts

●

Malfunctioning seal of air cleaner element

●

Uneven dirt of air cleaner element

●

Improper specification of intake air system parts

If NG, repair or replace malfunctioning part and perform step 2 to 4 again.
If OK, go to next step.

Turn ignition switch OFF.

Disconnect mass air flow sensor harness connector and reconnect it again.

Perform step 2 to 4 again.

If NG, clean or replace mass air flow sensor.

Without CONSULT-II

Reconnect all harness connectors disconnected.

Start engine and warm it up to normal operating temperature.

Check voltage between ECM terminal 51 (Mass air flow sensor
signal) and ground.

*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.

If the voltage is out of specification, proceed the following.

Check for the cause of uneven air flow through mass air flow sensor. Refer to following.

●

Crushed air ducts

●

Malfunctioning seal of air cleaner element

●

Uneven dirt of air cleaner element

●

Improper specification of intake air system parts

If NG, repair or replace malfunctioning part and perform step 2 to 3 again.
If OK, go to next step.

Turn ignition switch OFF.

Disconnect mass air flow sensor harness connector and reconnect it again.

Perform step 2 and 3 again.

If NG, clean or replace mass air flow sensor.

Condition

MAS A/F SE-B1 (V)

Ignition switch ON (Engine stopped.)

Approx. 0.4

Idle (Engine is warmed-up to normal
operating temperature.)

0.9 - 1.2

2,500 rpm (Engine is warmed-up to
normal operating temperature.)

1.5 - 1.8

Idle to about 4,000 rpm*

0.9 - 1.2 to Approx. 2.4

PBIB2371E

Condition

Voltage V

Ignition switch ON (Engine stopped.)

Approx. 0.4

Idle (Engine is warmed-up to normal
operating temperature.)

0.9 - 1.2

2,500 rpm (Engine is warmed-up to
normal operating temperature.)

1.5 - 1.8

Idle to about 4,000 rpm*

0.9 - 1.2 to Approx. 2.4

PBIB1106E

DTC P0101 MAF SENSOR

EC-191

2005 Pathfinder

Removal and Installation

UBS00K5H

MASS AIR FLOW SENSOR

Refer to

EM-15, "AIR CLEANER AND AIR DUCT"

EC-192

DTC P0102, P0103 MAF SENSOR

2005 Pathfinder

DTC P0102, P0103 MAF SENSOR

PFP:22680

Component Description

UBS00K5I

The mass air flow sensor is placed in the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. The mass air flow sensor controls the temperature of the hot
wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, electric current is supplied to hot wire is changed to main-
tain the temperature of the hot wire as air flow increases. The ECM
detects the air flow by means of this current change.

CONSULT-II Reference Value in Data Monitor Mode

UBS00K5J

Specification data are reference values.

On Board Diagnosis Logic

UBS00K5K

These self-diagnoses have the one trip detection logic.

FAIL-SAFE MODE

When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.

PBIB1604E

MONITOR ITEM

CONDITION

SPECIFICATION

MAS A/F SE-B1

See

EC-148, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE"

CAL/LD VALUE

●

Engine: After warming up

●

Shift lever: P or N

●

Air conditioner switch: OFF

●

No-load

Idle

5% - 35%

2,500 rpm

5% - 35%

MASS AIRFLOW

●

Engine: After warming up

●

Shift lever: P or N

●

Air conditioner switch: OFF

●

No-load

Idle

2.0 - 6.0 g·m/s

2,500 rpm

7.0 - 20.0 g·m/s

DTC No.

Trouble diagnosis

name

DTC detecting condition

Possible cause

P0102
0102

Mass air flow sensor
circuit low input

An excessively low voltage from the sensor is
sent to ECM.

●

Harness or connectors
(The sensor circuit is open or shorted.)

●

Intake air leaks

●

Mass air flow sensor

P0103
0103

Mass air flow sensor
circuit high input

An excessively high voltage from the sensor is
sent to ECM.

●

Harness or connectors
(The sensor circuit is open or shorted.)

●

Mass air flow sensor

Detected items

Engine operating condition in fail-safe mode

Mass air flow sensor circuit

Engine speed will not rise more than 2,400 rpm due to the fuel cut.

DTC P0102, P0103 MAF SENSOR

EC-193

2005 Pathfinder

DTC Confirmation Procedure

UBS00K5L

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

PROCEDURE FOR DTC P0102

With CONSULT-II

Turn ignition switch ON.

Select “DATA MONITOR” mode with CONSULT-II.

Start engine and wait at least 5 seconds.

If DTC is detected, go to

EC-195, "Diagnostic Procedure"

With GST

Follow the procedure “With CONSULT-II” above.

PROCEDURE FOR DTC P0103

With CONSULT-II

Turn ignition switch ON.