Nissan Frontier D22. Manual — part 541

TROUBLE DIAGNOSIS

EC-1267

[VG33ER]

C

D

E

F

G

H

I

J

K

L

M

A

EC

Circuit Diagram

UBS00DS9

BBWA0507E

EC-1268

[VG33ER]

TROUBLE DIAGNOSIS

ECM Harness Connector Terminal Layout

UBS00DSA

ECM Terminals and Reference Value

UBS00DSB

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

TROUBLE DIAGNOSIS

EC-1269

[VG33ER]

C

D

E

F

G

H

I

J

K

L

M

A

EC

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

EC-1270

[VG33ER]

TROUBLE DIAGNOSIS

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)

6

G/W

SCB valve control sole-
noid valve

[Ignition switch: ON]

●

Engine stopped

BATTERY VOLTAGE
(11 - 14V)

[Engine is running]

●

Idle speed

Approximately 0V

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)

TER-

MINAL

NO.

WIRE

COLOR

ITEM

CONDITION

DATA (DC Voltage)

SEF994U

SEF995U