Infiniti QX56 (JA60). Manual - part 365

 

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Infiniti QX56 (JA60). Manual - part 365

 

 

EC-112

< COMPONENT DIAGNOSIS >

[VK56DE]

P0102, P0103 MAF SENSOR

3. Check voltage between MAF sensor terminal 2 and ground with

CONSULT-III or tester.

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

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.

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 67.

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 4 and ECM terminal 51.

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-112, "Component Inspection"

.

OK or NG

OK

>> GO TO 9.

NG

>> Replace mass air flow sensor.

9.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-35, "How to Check Terminal"

 and 

GI-38, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005149120

MASS AIR FLOW SENSOR

Voltage: Battery voltage

PBIB1168E

Continuity should exist.

Continuity should exist.

P0102, P0103 MAF SENSOR

EC-113

< COMPONENT DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

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M

A

EC

N

P

O

 With CONSULT-III

1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-III and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check indication under the following conditions.

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

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

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

If OK, go to next step.

6. Turn ignition switch OFF.
7. Disconnect mass air flow sensor harness connector and reconnect it again.
8. Perform step 2 to 4 again.
9. If NG, clean or replace mass air flow sensor.

 Without CONSULT-III

1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. 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.

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

b. If NG, repair or replace malfunctioning part and perform step 2 and 3 again.

If OK, go to next step.

5. Turn ignition switch OFF.
6. Disconnect mass air flow sensor harness connector and reconnect it again.
7. Perform step 2 and 3 again.

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 - 1.3

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

1.7 - 2.1

Idle to about 4,000 rpm

0.9 - 1.3 to Approx. 2.4*

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 - 1.3

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

1.7 - 2.1

Idle to about 4,000 rpm

0.9 - 1.3 to Approx. 2.4*

PBIB1106E

EC-114

< COMPONENT DIAGNOSIS >

[VK56DE]

P0102, P0103 MAF SENSOR

8. If NG, clean or replace mass air flow sensor.

P0112, P0113 IAT SENSOR

EC-115

< COMPONENT DIAGNOSIS >

[VK56DE]

C

D

E

F

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EC

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P

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P0112, P0113 IAT SENSOR

Component Description

INFOID:0000000005149121

The intake air temperature sensor is built-into mass air flow sensor.

The sensor detects intake air temperature and transmits a signal to

the ECM.

The temperature sensing unit uses a thermistor which is sensitive to

the change in temperature. Electrical resistance of the thermistor

decreases in response to the temperature rise.

<Reference data>

*: This data is reference value and is measured between ECM terminal 34 (Intake air
temperature sensor) and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output

voltage. Doing so may result in damage to the ECM's transistor.

Use a ground other than ECM terminals, such as the ground.

On Board Diagnosis Logic

INFOID:0000000005149122

DTC Confirmation Procedure

INFOID:0000000005149123

1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting the next step.

a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Wait at least 5 seconds.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to 

EC-115, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000005149124

1.

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

2. Loosen and retighten three ground screws on the body.

BBIA0355E

Intake air temperature

°C (°F)]

Voltage* (V)

Resistance (k

Ω)

25 (77)

3.3

1.800 - 2.200

80 (176)

1.2

0.283 - 0.359

SEF012P

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0112
0112

Intake air temperature 
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 temperature sensor

P0113
0113

Intake air temperature 
sensor circuit high input

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

 

 

 

 

 

 

 

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