Infiniti QX56 (Z62). Manual - part 566

EC-242

< DTC/CIRCUIT DIAGNOSIS >

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P0133, P0153 A/F SENSOR 1

• Before installing new A/F sensor, clean exhaust system threads using Oxygen Sensor Thread

Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant
(commercial service tool).

>> INSPECTION END

P0137, P0157 HO2S2

EC-243

< DTC/CIRCUIT DIAGNOSIS >

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P0137, P0157 HO2S2

DTC Logic

INFOID:0000000006217813

DTC DETECTION LOGIC

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 various driving conditions such as fuel cut.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

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.

Will CONSULT-III be used?

YES

>> GO TO 2.

NO

>> GO TO 4.

2.

PERFORM DTC CONFIRMATION PROCEDURE

 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.

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

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Turn ignition switch ON.

4.

Turn ignition switch OFF and wait at least 10 seconds.

5.

Restart engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no
load.

6.

Let engine idle for 1 minute.

7.

Select “DATA MONITOR” mode with CONSULT-III.

8.

Check that “COOLAN TEMP/S” indicates more than 70

°

C (158

°

F).

If not, warm up engine and go to next step when “COOLAN TEMP/S” indication reaches 70

°

C (158

°

F).

9.

Open engine hood.

10. Select “HO2S2 (B1) P1147” (for DTC P0137) or “HO2S2 (B2) P1167” (for DTC P0157) of “HO2S2” in

“DTC WORK SUPPORT” mode with CONSULT-III.

11. Follow the instruction of CONSULT-III display.

NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.

12. Touch “SELF-DIAG RESULTS”.

JMBIA1572GB

DTC No.

Trouble diagnosis name

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P0137

HO2S2 (B1)
[Heated oxygen sensor 2 
(bank 1) circuit low voltage]

The maximum voltage from the sensor does 
not reach the specified voltage.

• Harness or connectors

(The heated oxygen sensor 2 circuit is 
open or shorted)

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

P0157

HO2S2 (B2)
[Heated oxygen sensor 2 
(bank 2) circuit low voltage]

EC-244

< DTC/CIRCUIT DIAGNOSIS >

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P0137, P0157 HO2S2

Which is displayed on CONSULT-III screen?

OK

>> INSPECTION END

NG

>> Go to 

EC-245, "Diagnosis Procedure"

.

CAN NOT BE DIAGNOSED>>GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE AGAIN

1.

Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).

2.

Perform DTC confirmation procedure again.

>> GO TO 2.

4.

PERFORM COMPONENT FUNCTION CHECK

 WITH GST

Perform component function check. Refer to 

EC-244, "Component Function Check"

.

NOTE:
Use component function check to check the overall function of the heated oxygen sensor 2 circuit. During this
check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-245, "Diagnosis Procedure"

.

Component Function Check

INFOID:0000000006217814

1.

PERFORM COMPONENT FUNCTION CHECK-I

 WITH GST

1.

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

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Turn ignition switch ON.

4.

Turn ignition switch OFF and wait at least 10 seconds.

5.

Restart engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no
load.

6.

Let engine idle for 1 minute.

7.

Check the voltage between ECM harness connector terminals under the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

PERFORM COMPONENT FUNCTION CHECK-II

Check the voltage between ECM harness connector terminals under the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 3.

DTC

ECM

Condition

Voltage

Connector

+

–

Terminal

Terminal

P0137

F110

96

100

Revving up to 4,000 rpm under no load at 
least 10 times

The voltage should be above 0.74 V at 
least once during this procedure.

P0157

87

DTC

ECM

Condition

Voltage

Connector

+

–

Terminal

Terminal

P0137

F110

96

100

Keeping engine at idle for 10 minutes

The voltage should be above 0.74 V at 
least once during this procedure.

P0157

87

P0137, P0157 HO2S2

EC-245

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3.

PERFORM COMPONENT FUNCTION CHECK-III

Check the voltage between ECM harness connector terminals under the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-245, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000006217815

1.

CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

1.

Clear the mixture ratio self-learning value. Refer to 

EC-152, "Work Procedure"

.

2.

Run engine for at least 10 minutes at idle speed.

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

YES

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

EC-263, "DTC Logic"

.

NO

>> GO TO 2.

2.

CHECK HEATED OXYGEN SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect heated oxygen sensor 2 (HO2S2) harness connector.

3.

Disconnect ECM harness connector.

4.

Check the continuity between HO2S2 harness connector and ECM harness connector.

5.

Also check harness for short to ground and short to power.

Is the inspection result normal?

YES

>> GO TO 3.

NO

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

3.

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check the continuity between HO2S2 harness connector and ECM harness connector.

2.

Check the continuity between HO2S2 harness connector and ground, or ECM harness connector and
ground.

DTC

ECM

Condition

Voltage

Connector

+

–

Terminal

Terminal

P0137

F110

96

100

Coasting from 80 km/h (50 MPH) with se-
lector lever in the D position

The voltage should be above 0.74 V at 
least once during this procedure.

P0157

87

DTC

HO2S2

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0137

1

F87

1

F110

100

Existed

P0157

2

F88

1

DTC

HO2S2

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0137

1

F87

4

F110

96

Existed

P0157

2

F88

4

87

DTC

HO2S2

ECM

Ground

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0137

1

F87

4

F110

96

Ground

Not existed

P0157

2

F88

4

87