Nissan Altima L32. Instruction — part 265

P0112, P0113 IAT SENSOR

EC-181

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

P0112, P0113 IAT SENSOR

Description

INFOID:0000000004349221

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

(1). 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>

*: These data are reference values and are measured between ECM terminal 50
(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.

DTC Logic

INFOID:0000000004349222

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at

least 10 seconds before conducting the next test.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1. Turn ignition switch ON and wait at least 5 seconds.

2. Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Go to

EC-182, "Diagnosis Procedure"

.

NO

>> INSPECTION END

PBIA9559J

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

Intake air tempera-
ture 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

Intake air tempera-
ture sensor circuit
high input

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

EC-182

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

P0112, P0113 IAT SENSOR

Diagnosis Procedure

INFOID:0000000004349223

1.

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

2. Check ground connection E9. Refer to Ground Inspection in

GI-45, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

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 the voltage between mass air flow sensor harness con-

nector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair open circuit or short to ground or short to power

in 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 the continuity between mass air flow sensor harness connector and ECM harness connector.

4. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 4.

NO

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

4.

CHECK INTAKE AIR TEMPERATURE SENSOR

Refer to

EC-182, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

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

5.

CHECK INTERMITTENT INCIDENT

Refer to

GI-42, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004349224

1.

CHECK INTAKE AIR TEMPERATURE SENSOR

1. Turn ignition switch OFF.

2. Disconnect mass air flow sensor harness connector.

MAF sensor

Ground

Voltage

Connector

Terminal

F31

2

Ground

Approx. 5 V

PBIB1168E

MAF sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

F31

1

F13

56

Existed

P0112, P0113 IAT SENSOR

EC-183

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

3. Check resistance between mass air flow sensor terminals as fol-

lows.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace mass air flow sensor (with intake air tempera-

ture sensor).

Terminals

Condition

Resistance k

Ω

1 and 2

Intake air temperature

°C (°F) 25 (77)

1.800 - 2.200

JMBIA1624ZZ

EC-184

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

P0116 ECT SENSOR

P0116 ECT SENSOR

Description

INFOID:0000000004349225

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>

*: These data are reference values and are measured between ECM terminals 46
(Engine coolant 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 transis-
tor. Use a ground other than ECM terminals, such as the ground.

DTC Logic

INFOID:0000000004349226

DTC DETECTION LOGIC

NOTE:

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

P0118. Refer to

EC-186, "DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC confirmation procedure has been previously conducted, always turn ignition switch OFF and wait at

least 10 seconds before conducting the next test.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine and warm it up to normal operating temperature.

2. Rev engine up to 2,000 rpm for more than 10 minutes.

3. Move the vehicle to a cool place, then stop engine and turn ignition switch OFF.

4. Check resistance between “fuel level sensor unit and fuel pump” terminals 4 and 5.

SEF594K

Engine coolant temperature

[

°C (°F)]

Voltage* (V)

Resistance (k

Ω)

–10 (14)

4.4

7.0 - 11.4

20 (68)

3.5

2.37 - 2.63

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

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