Infiniti QX56 (JA60). Manual - part 366

EC-116

< COMPONENT DIAGNOSIS >

[VK56DE]

P0112, P0113 IAT SENSOR

Refer to 

EC-85, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK INTAKE AIR TEMPERATURE SENSOR POWER SUPPLY CIRCUIT

1. Disconnect mass air flow sensor (with intake air temperature

sensor) harness connector.

2. Turn ignition switch ON.

3. Check voltage between mass air flow sensor terminal 5 and

ground.

OK or NG

OK

>> GO TO 3.

NG

>> Repair harness or connectors.

3.

CHECK INTAKE AIR TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check harness continuity between mass air flow sensor terminal 6 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 4.

NG

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

4.

CHECK INTAKE AIR TEMPERATURE SENSOR

Refer to 

EC-117, "Component Inspection"

.

OK or NG

OK

>> GO TO 5.

NG

>> Replace mass air flow sensor (with intake air temperature sensor).

BBIA0354E

BBIA0368E

Voltage: Approximately 5 V

PBIB1169E

Continuity should exist.

P0112, P0113 IAT SENSOR

EC-117

< COMPONENT DIAGNOSIS >

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5.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-35, "How to Check Terminal"

 and 

GI-38, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005149125

INTAKE AIR TEMPERATURE SENSOR

1. Check resistance between mass air flow sensor terminals 5 and

6 under the following conditions.

2. If NG, replace mass air flow sensor (with intake air temperature

sensor).

Intake air temperature 

°C (°F)]

Resistance (k

Ω)

25 (77)

1.800 - 2.200

BBIA0355E

SEF012P

EC-118

< COMPONENT DIAGNOSIS >

[VK56DE]

P0116 ECT SENSOR

P0116 ECT SENSOR

Component Description

INFOID:0000000005149126

The engine coolant temperature sensor is used to detect the engine

coolant temperature. The sensor modifies a voltage signal from the

ECM. The modified signal returns to the ECM as the engine coolant

temperature input. The sensor uses a thermistor which is sensitive to

the change in temperature. The electrical resistance of the ther-

mistor decreases as temperature increases.

<Reference data>

*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) 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.

On Board Diagnosis Logic

INFOID:0000000005149127

NOTE:

If DTC P0116 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117,

P0118. Refer to 

EC-122, "DTC Confirmation Procedure"

.

DTC Confirmation Procedure

INFOID:0000000005149128

NOTE:

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

before conducting the next step.

• Turn ignition switch OFF and wait at least 10 seconds.

• Turn ignition switch ON.

• Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

Before performing the following procedure, do not fill with the fuel.
1. Start engine and warm it up to normal operating temperature.
2. Rev engine up to 2,000 rpm for more than10 minutes.
3. Move the vehicle to a cool place, then stop engine and turn ignition switch OFF.
4. Check resistance between “fuel level sensor and fuel pump” terminals 3 and 4.

SEF594K

Engine coolant 

temperature

°C (°F)]

Voltage* (V)

Resistance (k

Ω)

−10 (14)

4.4

7.0 - 11.4

20 (68)

3.5

2.1 - 2.9

50 (122)

2.2

0.68 - 1.00

90 (194)

0.9

0.236 - 0.260

SEF012P

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0116
0116

Engine coolant tempera-
ture sensor circuit range/
performance

Engine coolant temperature signal from engine 
coolant temperature sensor does not fluctuate, 
even when some time has passed after starting 
the engine with pre-warming up condition.

• Harness or connectors

(High or low resistance in the circuit)

• Engine coolant temperature sensor

P0116 ECT SENSOR

EC-119

< COMPONENT DIAGNOSIS >

[VK56DE]

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5. Soak the vehicle until the resistance between “fuel level sensor and fuel pump” terminals 3 and 4

becomes 0.5 k

Ω higher than the value measured before soaking.

CAUTION:

Never turn ignition switch ON during the soaking time.

NOTE:

Soak time changes depending on ambient air temperature. It may take several hours.

6. Start engine and let it idle for 5 minutes.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to 

EC-119, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000005149129

1.

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

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

Refer to 

EC-85, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EC-119, "Component Inspection"

.

OK or NG

OK

>> GO TO 3.

NG

>> Replace engine coolant temperature sensor.

3.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-35, "How to Check Terminal"

 and 

GI-38, "Intermittent Incident"

.

For Wiring Diagram, refer to 

EC-435, "Wiring Diagram - ENGINE CONTROL SYSTEM -"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005149130

ENGINE COOLANT TEMPERATURE SENSOR

1. Check resistance between engine coolant temperature sensor

terminals 1 and 2 as shown in the figure.

BBIA0354E

PBIB2005E