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Infiniti M45 (Y34). Manual - part 373

DTC P0101 MAF SENSOR

EC-181

Component Inspection

ABS002F7

MASS AIR FLOW SENSOR

Reconnect all harness connectors disconnected.

Start engine and warm it up to normal operating temperature.

Check voltage between ECM terminal 91 (Mass air flow sensor
signal) and ground.

*: Make sure linear voltage rises as engine speed increase to about 4,000 rpm.

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

●

Turn ignition switch OFF.

●

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

●

Perform steps 2 and 3 again.

If NG, remove mass air flow sensor from air duct. Check hot film for damage or dust.

If NG, clean or replace mass air flow sensor.

Removal and Installation

ABS002F8

MASS AIR FLOW SENSOR

Refer to

EM-16, "AIR CLEANER AND AIR DUCT"

Condition

Voltage V

Ignition switch: ON (Engine stopped.)

Approx. 1.0

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

1.1 - 1.5

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

1.7 - 2.4

Idle to about 4,000 rpm*

1.1 - 1.5 to Approx. 4.0

PBIB0078E

EC-182

DTC P0102, P0103 MAF SENSOR

PFP:22680

Component Description

ABS002F9

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. It consists of a hot film that is supplied with electric current from
the ECM. The temperature of the hot film is controlled by the ECM a
certain amount. The heat generated by the hot film is reduced as the
intake air flows around it. The more air, the greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot film as air flow increases. The ECM
detects the air flow by means of this current change.

CONSULT-II Reference Value in Data Monitor Mode

ABS002FA

Specification data are reference values.

On Board Diagnosis Logic

ABS002FB

NOTE:
If DTC P0102, P0103 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229.
Refer to

EC-531

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.

SEC266C

MONITOR ITEM

CONDITION

SPECIFICATION

MAS A/F SE-B1

See

EC-128, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE"

CAL/LD VALUE

●

Engine: After warming up

●

Selector lever: P or N

●

Air conditioner switch: OFF

●

No load

Idle

15% - 35%

2,500 rpm

10% - 35%

MASS AIRFLOW

●

Engine: After warming up

●

Selector lever: P or N

●

Air conditioner switch: OFF

●

No load

Idle

3.8 - 5.2 g·m/s

2,500 rpm

16.0 - 21.5 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 when engine is running.

●

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-183

DTC Confirmation Procedure

ABS002FC

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-185, "Diagnostic Procedure"

With GST

Follow the procedure With CONSULT-II above.

PROCEDURE FOR DTC P0103

With CONSULT-II

Turn ignition switch ON.