Infiniti QX56 (JA60). Manual - part 442

EC-420

< COMPONENT DIAGNOSIS >

[VK56DE]

REFRIGERANT PRESSURE SENSOR

Refer to 

EC-85, "Ground Inspection"

.

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace ground connections.

3.

CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT

1. Disconnect refrigerant pressure sensor harness connector.

2. Turn ignition switch ON.

3. Check voltage between refrigerant pressure sensor terminal 1

and ground with CONSULT-III or tester.

OK or NG

OK

>> GO TO 5.

NG

>> GO TO 4.

4.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors E5, F14

• Harness for open or short between ECM and refrigerant pressure sensor

>> Repair harness or connectors.

5.

CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check harness continuity between refrigerant pressure sensor terminal 3 and ECM terminal 67.

Refer to Wiring Diagram.

4. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

BBIA0354E

BBIA0445E

Voltage: Approximately 5 V

PBIB0188E

Continuity should exist.

REFRIGERANT PRESSURE SENSOR

EC-421

< COMPONENT DIAGNOSIS >

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6.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors E5, F14

• Harness for open or short between ECM and refrigerant pressure sensor

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

7.

CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Check harness continuity between ECM terminal 70 and refrigerant pressure sensor terminal 2.

Refer to Wiring Diagram.

2. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 9.

NG

>> GO TO 8.

8.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors E5, F14

• Harness for open or short between ECM and refrigerant pressure sensor

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

9.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-35, "How to Check Terminal"

 and 

GI-38, "Intermittent Incident"

.

OK or NG

OK

>> Replace refrigerant pressure sensor.

NG

>> Repair or replace. 

Continuity should exist.

EC-422

< ECU DIAGNOSIS >

[VK56DE]

ECM

ECU DIAGNOSIS

ECM

CONSULT-lll Reference Value in Data Monitor Mode

INFOID:0000000005149492

Remarks:
z

 Specification data are reference values.

z

 Specification data are output/input values which are detected or supplied by the ECM at the connector.

* Specification data may not be directly related to their components signals/values/operations.
i.e. Adjust ignition timing with a timing light before monitoring IGN TIMING, because the monitor may show the specification data in spite of the

ignition timing not being adjusted to the specification data. This IGN TIMING monitors the data calculated by the ECM according to the signals

input from the camshaft position sensor and other ignition timing related sensors.

MONITOR ITEM

CONDITION

SPECIFICATION

ENG SPEED

• Run engine and compare CONSULT-IIl value with the tachometer indica-

tion.

Almost the same speed as the 
tachometer indication.

MAS A/F SE-B1

See 

EC-74

.

B/FUEL SCHDL

See 

EC-74

.

A/F ALPHA-B1
A/F ALPHA-B2

See 

EC-74

.

COOLAN TEMP/S

• Engine: After warming up

More than 70

°C (158°F)

A/F SEN1 (B1)
A/F SEN1 (B2)

• Engine: After warming up

Maintaining engine speed at 2,000 rpm Fluctuates around 2.2 V

HO2S2 (B1)
HO2S2 (B2)

• Revving engine from idle to 3,000 rpm quickly 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 - 0.3V 

←→ Approx. 0.6 - 1.0V

HO2S2 MNTR (B1)
HO2S2 MNTR (B2)

• Revving engine from idle to 3,000 rpm quickly 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

LEAN 

←→ RICH

VHCL SPEED SE

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

indication.

Almost the same speed as the 
speedometer indication

BATTERY VOLT

• Ignition switch: ON (Engine stopped)

11 - 14V

ACCEL SEN 1

• Ignition switch: ON

(Engine stopped)

Accelerator pedal: Fully released

0.5 - 1.0V

Accelerator pedal: Fully depressed

4.2 - 4.8V

ACCEL SEN 2*

1

• Ignition switch: ON

(Engine stopped)

Accelerator pedal: Fully released

0.5 - 1.0V

Accelerator pedal: Fully depressed

4.2 - 4.8V

TP SEN 1-B1
TP SEN 2-B1

• Ignition switch: ON

(Engine stopped)

• Selector lever: D

Accelerator pedal: Fully released

More than 0.36V

Accelerator pedal: Fully depressed

Less than 4.75V

EVAP SYS PRES

• Ignition switch: ON

Approx. 1.8 - 4.8V

START SIGNAL

• Ignition switch: ON 

→ START → ON

OFF 

→ ON → OFF

CLSD THL POS

• Ignition switch: ON

(Engine stopped)

Accelerator pedal: Fully released

ON

Accelerator pedal: Slightly depressed

OFF

AIR COND SIG

• Engine: After warming up, idle the 

engine

Air conditioner switch: OFF

OFF

Air conditioner switch: ON
(Compressor operates.)

ON

P/N POSI SW

• Ignition switch: ON

Selector lever: P or N

ON

Selector lever: Except above

OFF

PW/ST SIGNAL

• Engine: After warming up, idle the 

engine

Steering wheel: Not being turned
(Forward direction)

OFF

Steering wheel: Being turned

ON

ECM

EC-423

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LOAD SIGNAL

• Ignition switch: ON

Rear window defogger switch is ON 
and/or lighting switch is in 2nd.

ON

Rear window defogger switch is OFF 
and lighting switch is OFF.

OFF

IGNITION SW

• Ignition switch: ON 

→ OFF → ON

ON 

→ OFF → ON

HEATER FAN SW

• Engine: After warming up, idle the 

engine

Heater fan control switch: ON

ON

Heater fan control switch: OFF

OFF

BRAKE SW

• Ignition switch: ON

Brake pedal: Fully released

OFF

Brake pedal: Slightly depressed

ON

INJ PULSE-B1
INJ PULSE-B2

• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No load

Idle

2.0 - 2.8 msec

2,000 rpm

1.9 - 2.9 msec

IGN TIMING

• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No load

Idle

10

° - 20° BTDC

2,000 rpm

25

° - 45° BTDC

CAL/LD VALUE

• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No load

Idle

14% - 33%

2,500 rpm

12% - 25%

MASS AIRFLOW

• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No load

Idle

3.0 - 9.0 g·m/s

2,500 rpm

9.0 - 28.0 g·m/s

PURG VOL C/V

• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No load

Idle
(Accelerator pedal: Not depressed 
even slightly, after engine starting.)

0%

2,000 rpm

—

INT/V TIM (B1)
INT/V TIM (B2)

• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No load

Idle

−5° - 5°CA

2,000 rpm

Approx. 0

° - 20°CA

INT/V SOL (B1)
INT/V SOL (B2)

• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No load

Idle

0% - 2%

2,000 rpm

Approx. 25% - 50%

AIR COND RLY

• Engine: After warming up, idle the 

engine

Air conditioner switch: OFF

OFF

Air conditioner switch: ON
(Compressor: Operates)

ON

FUEL PUMP RLY

• For 1 second after turning ignition switch ON
• Engine running or cranking

ON

• Except above conditions

OFF

VENT CONT/V

• Ignition switch: ON

OFF

THRTL RELAY

• Ignition switch: ON

ON

COOLING FAN

• Engine: After warming up, idle the 

engine

• Air conditioner switch: OFF

Engine coolant temperature: 99

°C 

(210

°F) or less

OFF

Engine coolant temperature: 100

°C 

(212

°F) or more

HI

HO2S2 HTR (B1)
HO2S2 HTR (B2)

• 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

ON

• Engine speed: Above 3,600 rpm

OFF

MONITOR ITEM

CONDITION

SPECIFICATION