Infiniti QX56 (JA60). Manual - part 443

EC-424

< ECU DIAGNOSIS >

[VK56DE]

ECM

*1: Accelerator pedal position sensor 2 signal and throttle position sensor 2 signal are converted by ECM internally. Thus, they differ
from ECM terminals voltage signal.
*2: Before measuring the terminal voltage, confirm the battery is fully charged. Refer to 

PG-74

.

I/P PULLY SPD

• Vehicle speed: More than 20 km/h (12 MPH)

Almost the same speed as the 
tachometer indication

VEHICLE SPEED

• Turn drive wheels and compare CONSULT-IIl value with the speedometer 

indication.

Almost the same speed as the 
speedometer indication

TRVL AFTER MIL

• Ignition switch: ON

Vehicle has traveled after MIL has 
turned ON.

0 - 65,535 km
(0 - 40,723 mile)

A/F S1 HTR (B1)
A/F S1 HTR (B2)

• Engine: After warming up, idle the engine

4 - 100%

AC PRESS SEN

• Engine: Idle
• Both A/C switch and blower fan switch: ON (Compressor operates.)

1.0 - 4.0V

VHCL SPEED SE

• Turn drive wheels and compare CONSULT-IIl value with the speedometer 

indication.

Almost the same speed as the 
speedometer indication

SET VHCL SPD

• Engine: Running

ASCD: Operating.

The preset vehicle speed is dis-
played.

MAIN SW

• Ignition switch: ON

MAIN switch: Pressed

ON

MAIN switch: Released

OFF

CANCEL SW

• Ignition switch: ON

CANCEL switch: Pressed

ON

CANCEL switch: Released

OFF

RESUME/ACC SW

• Ignition switch: ON

RESUME/ACCELERATE switch: 
Pressed

ON

RESUME/ACCELERATE switch: Re-
leased

OFF

SET SW

• Ignition switch: ON

SET/COAST switch: Pressed

ON

SET/COAST switch: Released

OFF

DIST SW

• Ignition switch: ON

DISTANCE switch: Pressed

ON

DISTANCE switch: Released

OFF

BRAKE SW1

• Ignition switch: ON

Brake pedal: Fully released

ON

Brake pedal: Slightly depressed

OFF

BRAKE SW2

• Ignition switch: ON

Brake pedal: Fully released

OFF

Brake pedal: Slightly depressed

ON

CRUISE LAMP

• Ignition switch: ON

MAIN switch: Pressed at the 1st time 
→ at the 2nd time

ON 

→ OFF

SET LAMP

• MAIN switch: ON
• Vehicle speed: Between 40 km/h 

(25 MPH) and 144 km/h (89 
MPH)

ASCD: Operating

ON

ASCD: Not operating

OFF

ALT DUTY

• Engine: Idle

0 - 80%

BAT CUR SEN

• Engine speed: Idle
• Battery: Fully charged*

2

• Selector lever: P or N
• Air conditioner switch: OFF
• No  load

Approx. 2,600 - 3,500mV

ALT DUTY SIG

• Power generation voltage variable control: Operating

ON

• Power generation voltage variable control: Not operating

OFF

MONITOR ITEM

CONDITION

SPECIFICATION

ECM

EC-425

< ECU DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

ECM Harness Connector Terminal Layout

INFOID:0000000005149493

ECM Terminal and Reference Value

INFOID:0000000005149494

PREPARATION

ECM is located in the engine room passenger side behind battery.

ECM INSPECTION TABLE

Specification data are reference values and are measured between each terminal and ground.

Pulse signal is measured by CONSULT-IIl.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-

age to the ECMs transistor. Use a ground other than ECM terminals, such as the ground.

PBIB3368E

BBIA0386E

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

1

B

ECM ground

[Engine is running]
• Idle speed

Body ground

2

LG/B

A/F sensor 1 heater (bank 1)

[Engine is running]
• Warm-up condition
• Idle speed

(More than 140 seconds after starting en-
gine)

Approximately 2.9 - 8.8V

3

L

Throttle control motor relay 
power supply

[Ignition switch: ON]

BATTERY VOLTAGE
(11 - 14V)

4

L/W

Throttle control motor (Close)

[Ignition switch: ON]
• Engine: Stopped
• Selector lever: D
• Accelerator pedal: Fully released

0 - 14V

PBIA8148J

PBIB1104E

EC-426

< ECU DIAGNOSIS >

[VK56DE]

ECM

5

L/B

Throttle control motor (Open)

[Ignition switch: ON]
• Engine: Stopped
• Selector lever: D
• Accelerator pedal: Fully depressed

0 - 14V

6

GR

Heated oxygen sensor 2 heat-
er (bank 1)

[Engine is running]
• Engine speed: Below 3,600 rpm after the 

following conditions are met.

- Engine: After warming up
- Keeping the engine speed between 3,500 

and 4,000 rpm for 1 minute and at idle for 1 
minute under no load

0 - 1.0V

[Ignition switch: ON]
• Engine: Stopped
[Engine is running]
• Engine speed: Above 3,600 rpm

BATTERY VOLTAGE
(11 - 14V)

10

W

Intake valve timing control so-
lenoid valve (bank 1)

[Engine is running]
• Warm-up condition
• Idle speed

BATTERY VOLTAGE
(11 - 14V)

[Engine is running]
• Warm-up condition
• Engine speed: 2,000rpm

7 - 12V

11

LG

Intake valve timing control so-
lenoid valve (bank 2)

[Engine is running]
• Warm-up condition
• Idle speed

BATTERY VOLTAGE
(11 - 14V)

[Engine is running]
• Warm-up condition
• Engine speed: 2,000rpm

7 - 12V

12

R

Power steering pressure sen-
sor

[Engine is running]
• Steering wheel: Being turned

0.5 - 4.5V

[Engine is running]
• Steering wheel: Not being turned

0.4 - 0.8V

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

PBIB1105E

PBIB1790E

PBIB1790E

ECM

EC-427

< ECU DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

13

O

Crankshaft position sensor 
(POS)

[Engine is running]
• Warm-up condition
• Idle speed
NOTE:
The pulse cycle changes depending on rpm at 
idle

Approximately 10V

[Engine is running]
• Engine speed: 2,000 rpm

Approximately 10V

14

Y

Camshaft position sensor 
(PHASE)

[Engine is running]
• Warm-up condition
• Idle speed
NOTE:
The pulse cycle changes depending on rpm at 
idle

1.0 - 4.0V

[Engine is running]
• Engine speed: 2,000 rpm

1.0 - 4.0V

15

W

Knock sensor (bank 1)

[Engine is running]
• Idle speed

Approximately 2.5V

16

G

A/F sensor 1 (bank 1)

[Engine is running]
• Warm-up condition
• Engine speed: 2,000 rpm

Approximately 1.8V
Output voltage varies with air fuel 
ratio.

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

PBIB1041E

PBIB1042E

PBIB1039E

PBIB1040E