Content .. 373 374 375 376 ..

Infiniti QX56 (JA60). Manual - part 375

EC-152

< COMPONENT DIAGNOSIS >

[VK56DE]

P0133, P0153 A/F SENSOR 1

2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-III.

3. Clear the self-learning control coefficient by touching “CLEAR” or “START”.

4. Run engine for at least 10 minutes at idle speed.

Is the 1st trip DTC P0171, P172, P0174 or P0175 detected? Is it difficult to start engine?

Without CONSULT-III

1. Start engine and warm it up to normal operating temperature.

2. Turn ignition switch OFF.

3. Disconnect mass air flow sensor harness connector.

4. Restart engine and let it idle for at least 5 seconds.

5. Stop engine and reconnect mass air flow sensor harness con-

nector.

6. Make sure DTC P0102 is displayed.

7. Erase the DTC memory. Refer to

EC-55, "Malfunction Indicator

Lamp (MIL)"

8. Make sure DTC P0000 is displayed.

9. Run engine for at least 10 minutes at idle speed.

Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?

Is it difficult to start engine?

Yes or No

Yes

>> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to

EC-172

EC-177

>> GO TO 6.

CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect A/F sensor 1 harness connector.

3. Turn ignition switch ON.

4. Check voltage between A/F sensor 1 terminal 4 and ground with

CONSULT-III or tester.

OK or NG

>> GO TO 8.

>> GO TO 7.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors E5, F14

• IPDM E/R harness connector E119

• 15A fuse (No. 54)

• Harness for open or short between A/F sensor 1 and fuse

>> Repair or replace harness or connectors.

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

BBIA0368E

Voltage: Battery voltage

BBIA0376E

PBIB3308E

P0133, P0153 A/F SENSOR 1

EC-153

< COMPONENT DIAGNOSIS >

[VK56DE]

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.

Refer to Wiring Diagram.

4. Check harness continuity between the following terminals and ground.

Refer to Wiring Diagram.

5. Also check harness for short to power.
OK or NG

>> GO TO 9.

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

CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER

Refer to

EC-97, "Component Inspection"

OK or NG

>> GO TO 10.

>> GO TO 13.

10.

CHECK MASS AIR FLOW SENSOR

Refer to

EC-108, "Component Inspection"

OK or NG

>> GO TO 11.

>> Replace mass air flow sensor.

11.

CHECK PCV VALVE

Refer to

EC-417, "Component Inspection"

OK or NG

>> GO TO 12.

>> Repair or replace PCV valve.

12.

CHECK INTERMITTENT INCIDENT

Refer to

GI-35, "How to Check Terminal"

and

GI-38, "Intermittent Incident"

OK or NG

>> GO TO 13.

>> Repair or replace.

13.

REPLACE AIR FUEL RATIO (A/F) SENSOR 1

Replace malfunctioning air fuel ratio (A/F) sensor 1.

CAUTION:

A/F sensor 1 terminal

ECM terminal

Bank1

Bank 2

Continuity should exist.

Bank 1

Bank 2

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

ECM terminal

Continuity should not exist.

EC-154

< COMPONENT DIAGNOSIS >

[VK56DE]

P0133, P0153 A/F SENSOR 1

• Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m

(19.7 in) onto a hard surface such as a concrete floor; use a new one.

• Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sensor

Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.

>> INSPECTION END

P0137, P0157 HO2S2

EC-155

< COMPONENT DIAGNOSIS >

[VK56DE]

P0137, P0157 HO2S2

Component Description

INFOID:0000000005149172

The heated oxygen sensor 2, after three way catalyst (manifold),

monitors the oxygen level in the exhaust gas on each bank.

Even if switching characteristics of the air fuel ratio (A/F) sensor 1

are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-

nal from the heated oxygen sensor 2.

This sensor is made of ceramic zirconia. The zirconia generates volt-

age from approximately 1V in richer conditions to 0V in leaner condi-

tions.

Under normal conditions the heated oxygen sensor 2 is not used for

engine control operation.

On Board Diagnosis Logic

INFOID:0000000005149173

The heated oxygen sensor 2 has a much longer switching time

between rich and lean than the air fuel ratio (A/F) sensor 1. The oxy-

gen storage capacity of the three way catalyst (manifold) causes the

longer switching time. To judge the malfunctions of heated oxygen

sensor 2, ECM monitors whether the maximum voltage of the sensor

is sufficiently high during the various driving condition such as fuel-

cut.

DTC Confirmation Procedure

INFOID:0000000005149174

NOTE:

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.

WITH CONSULT-III

TESTING CONDITION:

For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30

°C (32 to 86 °F).

1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70

°C (158°F).

SEF327R

PBIB1154E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0137
0137
(Bank 1)

Heated oxygen sensor 2
circuit low voltage

The maximum voltage from the sensor is not
reached to the specified voltage.

• Harness or connectors

(The sensor circuit is open or shorted)

• Heated oxygen sensor 2
• Fuel pressure
• Fuel injector
• Intake air leaks

P0157
0157
(Bank 2)

Content .. 373 374 375 376 ..