Nissan Frontier D40. Manual - part 361

P0127 IAT SENSOR

EC-135

< COMPONENT DIAGNOSIS >

[QR25DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

SEF012P

EC-136

< COMPONENT DIAGNOSIS >

[QR25DE]

P0128 THERMOSTAT FUNCTION

P0128 THERMOSTAT FUNCTION

On Board Diagnosis Logic

INFOID:0000000005273122

NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303 or P0304, first perform the trouble
diagnosis for DTC P0300, P0301, P0302, P0303, P0304. Refer to 

EC-188, "DTC Confirmation Proce-

dure"

.

Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leak in the seal or the thermostat being stuck open.

DTC Confirmation Procedure

INFOID:0000000005273123

 With CONSULT-III

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.
TESTING CONDITION:
• For best results, perform at ambient temperature of –10

°

C (14

°

F) or higher.

• For best results, perform at engine coolant temperature of –10

°

C (14

°

F) to 56

°

C (133

°

F).

• Before performing the following procedure, do not add fuel.

1.

Turn A/C switch OFF.

2.

Turn blower fan switch OFF.

3.

Turn ignition switch ON.

4.

Select “COOLAN TEMP/S” in “DATA MONITOR” mode with CONSULT-III.

5.

Check the indication of “COOLAN TEMP/S”.
If it is below 56

°

C (133

°

F), go to next step.

If it is above 56

°

C (133

°

F), cool down the engine to less than 56

°

C (133

°

F). then go to next steps.

6.

Start engine and drive vehicle for 10 consecutive minutes under the following conditions.

CAUTION:

Always drive vehicle at a safe speed.
NOTE:
If “COOLAN TEMP/S” increases to more than 75

°

C (167

°

F) within 10 minutes, turn ignition switch

OFF because the test result will be OK.

7.

Check 1st trip DTC.

8.

If 1st trip DTC is detected, go to 

EC-136, "Diagnosis Procedure"

.

 With GST

Follow the procedure “With CONSULT-III” above.

Diagnosis Procedure

INFOID:0000000005273124

1.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EC-137, "Component Inspection"

.

OK or NG

OK

>> GO TO 2.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0128
0128

Thermostat function

The engine coolant temperature does not 
reach to specified temperature even though 
the engine has run long enough.

• Thermostat
• Leakage from sealing portion of thermostat
• Engine coolant temperature sensor

VHCL SPEED SE

More than 56km/h (35 MPH)

P0128 THERMOSTAT FUNCTION

EC-137

< COMPONENT DIAGNOSIS >

[QR25DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

NG

>> Replace engine coolant temperature sensor.

2.

CHECK THERMOSTAT

Refer to 

CO-22, "Removal and Installation Thermostat"

.

OK or NG

OK

>> INSPECTION END

NG

>> Replace thermostat.

Component Inspection

INFOID:0000000005273125

ENGINE COOLANT TEMPERATURE SENSOR

1.

Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.

<Reference data>

2.

If NG, replace engine coolant temperature sensor.

PBIB2005E

Engine coolant temperature [

°

C (

°

F)]

Resistance

(k

Ω

)

20 (68)

2.1 - 2.9

50 (122)

0.68 - 1.00

90 (194)

0.236 - 0.260

SEF012P

EC-138

< COMPONENT DIAGNOSIS >

[QR25DE]

P0130 A/F SENSOR 1

P0130 A/F SENSOR 1

Component Description

INFOID:0000000005273126

The A/F sensor 1 is a planar dual-cell limit current sensor. The sen-
sor element of the A/F sensor 1 is the combination of a Nernst con-
centration cell (sensor cell) with an oxygen-pump cell, which
transports ions. It has a heater in the element.
The sensor is capable of precise measurement   = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide   range (0.7 <

 < air).

The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.

An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at   = 1. Therefore, the A/F sensor 1 is able to
indicate air-fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800

°

C (1,292 - 1,472

°

F).

On Board Diagnosis Logic

INFOID:0000000005273127

To judge malfunctions, the diagnosis checks that the A/F signal computed by ECM from the air fuel ratio (A/F)
sensor 1 signal fluctuates according to fuel feedback control.

DTC Confirmation Procedure

INFOID:0000000005273128

Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

PROCEDURE FOR MALFUNCTION A

 With CONSULT-III

1.

Start engine and warm it up to normal operating temperature.

2.

Let engine idle for 2 minutes.

3.

Check 1st trip DTC.

4.

If 1st trip DTC is detected, go to 

EC-139, "Diagnosis Procedure"

.

SEF579Z

SEF580Z

DTC 

No.

Trouble diagnosis name

DTC detecting condition

Possible Cause

P0130
0130

Air fuel ratio (A/F) sensor 1 circuit

A)

The A/F signal computed by ECM from the 
A/F sensor 1 signal is constantly in a range 
other than approx. 1.5V.

• Harness or connectors

(A/F sensor 1 circuit is open or 
shorted.)

• Air fuel ratio (A/F) sensor 1

B)

The A/F signal computed by ECM from the 
A/F sensor 1 signal is constantly approx. 
1.5V.