Nissan Frontier D22. Manual - part 391

TROUBLE DIAGNOSIS

EC-667

[VG33E]

C

D

E

F

G

H

I

J

K

L

M

A

EC

ECM Harness Connector Terminal Layout

UBS00DF8

ECM Terminals and Reference Value

UBS00DF9

PREPARATION

1.

ECM is located behind the instrument lower cover. For this
inspection:

●

Remove instrument lower cover.

2.

Remove ECM harness protector.

3.

Perform all voltage measurements with the connector con-
nected. Extend tester probe as shown to perform tests easily.

●

Open harness securing clip to make testing easier.

●

Use extreme care not to touch 2 pins at 1 time.

●

Data is for comparison and may not be exact.

ECM INSPECTION TABLE

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 the ECM terminals, such as the ground.

SEF533P

LEC106A

AEC913

MEC486B

EC-668

[VG33E]

TROUBLE DIAGNOSIS

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

1

PU/W

Ignition signal

[Engine is running]

●

Idle speed

NOTE:
The pulse cycle changes depending on rpm at 
idle

Approximately 0.7V

[Engine is running]

●

Engine speed is 2,000 rpm

1.1 - 1.5V

3

P/L

Tachometer

[Engine is running]

●

Warm-up condition

●

Idle speed

NOTE:
The pulse cycle changes depending on rpm at 
idle

1 - 2V

[Engine is running]

●

Engine speed is 2,000 rpm

3 - 5V

4

OR/B

ECM relay
(Self shutoff)

[Engine is running]
[Ignition switch: OFF]

●

For a few seconds after turning ignition switch 
OFF

0 - 1.5V

[Ignition switch: OFF]

●

A few seconds passed after turning ignition 
switch OFF

BATTERY VOLTAGE
(11 - 14V)

SEF988U

SEF989U

SEF992U

SEF993U

TROUBLE DIAGNOSIS

EC-669

[VG33E]

C

D

E

F

G

H

I

J

K

L

M

A

EC

5

R/Y

EVAP canister purge 
volume control solenoid 
valve

[Engine is running]

●

Idle speed

BATTERY VOLTAGE

(11 - 14V)

[Engine is running]

●

 Engine speed is 2,000 rpm (More than 100 
seconds after starting engine)

BATTERY VOLTAGE

(11 - 14V)

7

Y/G

A/T check signal

[Ignition switch: ON]
[Engine is running]

0 - 3.0V

9

B/Y

Ambient air tempera-
ture switch

[Engine is running]

●

Idle speed

●

Ambient air temperature is above 25

°C (77°F)

●

Air conditioner is operating

0V

[Engine is running]

●

Idle speed

●

Ambient air temperature is below 19

°C (66°F)

●

Air conditioner is operating

BATTERY VOLTAGE
(11 - 14V)

[Engine is running]

●

Idle speed

●

Ambient air temperature is below 19

°C (66°F)

●

Air conditioner is not operating

Approximately 5V

10 B/R

ECM 

ground

[Engine is running]

●

Idle speed

Engine ground

11

W/R

Fuel pump relay

[Ignition switch: ON]

●

For a few seconds after turning ignition switch 
ON

[Engine is running]

0 - 1V

[Ignition switch: ON]

●

A few seconds after turning ignition switch ON

BATTERY VOLTAGE
(11 - 14V)

12

P

Air conditioner relay

[Engine is running]

●

Both A/C switch and blower switch are ON*

0 - 1V

[Engine is running]

●

A/C switch is OFF

BATTERY VOLTAGE
(11 - 14V)

18

R/W

Malfunction indicator 
lamp

[Ignition switch: ON]

0 - 1V

[Engine is running]

●

Idle speed

BATTERY VOLTAGE
(11 - 14V)

19

B/R

ECM ground

[Engine is running]

●

Idle speed

Engine ground

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

SEF994U

SEF995U

EC-670

[VG33E]

TROUBLE DIAGNOSIS

20

L/OR

Start signal

[Ignition switch: ON]

Approximately 0V

[Ignition switch: START]

9 - 12V

21

G/R

Air conditioner switch

[Engine is running]

●

Both A/C switch and blower switch are ON 
(Compressor operates)*

Approximately 0V

[Engine is running]

●

A/C switch is OFF

BATTERY VOLTAGE
(11 - 14V)

22

L/B

Park/neutral position 
(PNP) switch

[Ignition switch: ON] 

●

Shift lever: P or N (A/T), Neutral (M/T)

Approximately 0V

[Ignition switch: ON]

●

Except above position

Approximately 5V

23

L

Throttle position sensor

[Engine is running]

●

Warm-up condition

●

More than -40.0 kpa (-300 mmHg, -11.81 inHg) 
of vacuum is applied to the throttle opener with 
a hand vacuum pump

●

Accelerator pedal is fully released

0.15 - 0.85V

 [Ignition switch: ON]

●

Engine stopped

●

Accelerator pedal is fully depressed

3.5 - 4.7V

24

W/L

Ignition switch

[Ignition switch: OFF]

0V

[Ignition switch: ON]

BATTERY VOLTAGE
(11 - 14V)

25

B/Y

ECM ground

[Engine is running]

●

Idle speed

Engine ground

26

PU/W

A/T signal No. 1

[Engine is running]

●

Idle speed

Approximately 0 - 1.0V

27

P/B

A/T signal No. 2

[Engine is running]

●

Idle speed

Approximately 0 - 1.0V

28

BR/W

Throttle position switch 
(Closed position)

[Engine is running]

●

Warm-up condition

●

More than -40.0 kpa (-300 mmHg, -11.81 inHg) 
of vacuum is applied to the throttle opener with 
a hand vacuum pump

●

Accelerator pedal is fully released

BATTERY VOLTAGE
(11 - 14V)

[Ignition switch: ON]

●

Engine stopped

●

Accelerator pedal is depressed

Approximately 0V

29

G/B

Vehicle speed sensor

[Engine is running]

●

Lift up the vehicle.

●

Shift lever: 2nd (M/T), D (A/T)

●

Vehicle speed is 40 km/h (25 MPH)

2 - 3V

32

B/Y

ECM ground

[Engine is running]

●

Idle speed

Engine ground 

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

SEF996U