Infiniti M35/M45 Y50. Manual - part 454

DTC P0138, P0158 HO2S2

EC-289

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

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 ECM terminals, such as the ground.

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

25

P/B

Heated oxygen sensor 2 
heater (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)

74

W

Heated oxygen sensor 2 
(bank 1)

[Engine is running]

●

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 - Approximately 1.0V

78

B

Sensor ground
(Heated oxygen sensor)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 0V

EC-290

[VQ35DE]

DTC P0138, P0158 HO2S2

BANK 2

TBWT1474E

DTC P0138, P0158 HO2S2

EC-291

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

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 ECM terminals, such as the ground.

Diagnostic Procedure

NBS004XG

PROCEDURE FOR MALFUNCTION A

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten two ground screws on the body.
Refer to 

EC-160, "Ground Inspection"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

6

R/L

Heated oxygen sensor 2 
heater (bank 2)

[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)

55

W

Heated oxygen sensor 2 
(bank 2)

[Engine is running]

●

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 - Approximately 1.0V

78

B

Sensor ground
(Heated oxygen sensor)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 0V

1.

Body ground M70

2.

Body ground M16

PBIB2782E

EC-292

[VQ35DE]

DTC P0138, P0158 HO2S2

2. 

CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Disconnect heated oxygen sensor 2 harness connector.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between ECM terminal 78 and HO2S2
terminal 1.
Refer to Wiring Diagram.

4.

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

OK or NG

OK

>> GO TO 3.

NG

>> Repair open circuit or short to ground or short to power

in harness or connectors.

3. 

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.

2.

Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.

3.

Also check harness for short to power.

OK or NG

OK

>> GO TO 4.

NG

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

4. 

CHECK HO2S2 CONNECTOR FOR WATER

Check connectors for water.

OK or NG

OK

>> GO TO 5.

NG

>> Repair or replace harness or connectors.

5. 

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-295, "Component Inspection"

 .

OK or NG

OK

>> GO TO 6.

NG

>> Replace malfunctioning heated oxygen sensor 2.

Continuity should exist.

PBIB1576E

DTC

Terminals

Bank

ECM

Sensor

P0138

74

4

1

P0158

55

4

2

Continuity should exist.

DTC

Terminals

Bank

ECM

Sensor

P0138

74

4

1

P0158

55

4

2

Continuity should not exist.

Water should not exist.