Infiniti M45 (Y34). Manual - part 372

DTC P0101 MAF SENSOR

EC-177

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Wiring Diagram

ABS002F5

TBWA0271E

EC-178

DTC P0101 MAF SENSOR

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

ABS002F6

1. 

INSPECTION START

Which malfunction (A or B) is duplicated?

A or B

A

>> GO TO 3.

B

>> GO TO 2.

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

OK

>> GO TO 3.

NG

>> Reconnect the parts.

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

42

W/B

ECM relay
(Self shut-off)

[Engine is running]
[Ignition switch: OFF]

●

A few seconds after turning ignition switch 
OFF

0 - 1.0V

[Ignition switch: OFF]

●

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

BATTERY VOLTAGE
(11 - 14V)

91

B/Y

Mass air flow sensor

[Engine is running]

●

Warm-up condition

●

Idle speed

1.1 - 1.5V

[Engine is running]

●

Warm-up condition

●

Engine speed: 2,500 rpm.

1.7 - 2.4V

103

L

Sensor power supply

[Ignition switch: ON]

Approximately 5V

109

LG

Mass air flow sensor ground

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 0V

163
166

R
R

Power supply for ECM

[Ignition switch: ON]

BATTERY VOLTAGE
(11 - 14V)

DTC P0101 MAF SENSOR

EC-179

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3. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten two ground screws. 
Refer to 

EC-141, "Ground Inspection"

 .

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace ground connections.

4. 

CHECK MAF SENSOR POWER SUPPLY CIRCUIT

1.

Disconnect mass air flow (MAF) sensor harness connector.

2.

Turn ignition switch ON.

3.

Check voltage between MAF sensor terminals 2, 4 and ground
with CONSULT-II or tester.

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

5. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M135, F105

●

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

●

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

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

PBIB1118E

PBIB1119E

Terminal

Voltage

2

Approximately 5V

4

Battery voltage

PBIB0076E

EC-180

DTC P0101 MAF SENSOR

6. 

CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between MAF sensor terminal 3 and ECM terminal 109.
Refer to Wiring Diagram.

4.

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

OK or NG

OK

>> GO TO 7.

NG

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

7. 

CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between MAF sensor terminal 1 and ECM terminal 91.
Refer to Wiring Diagram.

2.

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

OK or NG

OK

>> GO TO 8.

NG

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

8. 

CHECK MASS AIR FLOW SENSOR

Refer to 

EC-181, "Component Inspection"

 .

OK or NG

OK

>> GO TO 9.

NG

>> Replace mass air flow sensor.

9. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Continuity should exist.

Continuity should exist.