Infiniti M45 (Y34). Manual - part 368

DTC P0031, P0032, P0051, P0052 HO2S1 HEATER

EC-161

C

D

E

F

G

H

I

J

K

L

M

A

EC

BANK 2

TBWA0268E

EC-162

DTC P0031, P0032, P0051, P0052 HO2S1 HEATER

Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.

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.

: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)

Diagnostic Procedure

ABS002EP

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten two ground screws. 
Refer to 

EC-141, "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)

9

G/Y

Heated oxygen sensor 1 
heater (bank 2)

[Engine is running]

●

Warm-up condition

●

Engine speed: Below 3,000 rpm.

Approximately 7V

[Engine is running]

●

Engine speed: Above 3,000 rpm.

BATTERY VOLTAGE
(11 - 14V)

PBIB0519E

PBIB1118E

DTC P0031, P0032, P0051, P0052 HO2S1 HEATER

EC-163

C

D

E

F

G

H

I

J

K

L

M

A

EC

2. 

CHECK HO2S1 POWER SUPPLY CIRCUIT

1.

Disconnect heated oxygen sensor 1 harness connector.

2.

Turn ignition switch ON.

3.

Check voltage between HO2S1 terminal 3 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 3.

3. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E33, F33

●

Fuse block (J/B) No.1 connector E201

●

10A fuse

●

Harness for open or short between heated oxygen sensor 1 and fuse

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

4. 

CHECK HO2S1 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between ECM terminal and HO2S1 terminal as follows.
Refer to Wiring Diagram.

4.

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

OK or NG

OK

>> GO TO 5.

NG

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

Voltage: Battery voltage

PBIB0017E

PBIB0112E

DTC

Terminals

Bank

ECM

Sensor

P0031, P0032

8

2

1

P0051, P0052

9

2

2

Continuity should exist.

EC-164

DTC P0031, P0032, P0051, P0052 HO2S1 HEATER

5. 

CHECK HEATED OXYGEN SENSOR 1 HEATER

Refer to 

EC-164, "Component Inspection"

 .

OK or NG

OK

>> GO TO 6.

NG

>> Replace malfunctioning heated oxygen sensor 1.

6. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Component Inspection

ABS002EQ

HEATED OXYGEN SENSOR 1 HEATER

1.

Check resistance between HO2S1 terminals as follows.

2.

If NG, replace heated oxygen sensor 1.

CAUTION:

●

Discard any heated oxygen sensor which has been dropped
from a height of more than 0.5 m (19.7 in) onto a hard sur-
face such as a concrete floor; use a new one.

●

Before installing new oxygen sensor, clean exhaust system
threads using Oxygen Sensor Thread Cleaner tool J-43897-
18 or J-43897-12 and approved anti-seize lubricant.

Removal and Installation

ABS002ER

HEATED OXYGEN SENSOR 1

Refer to 

EM-22, "EXHAUST MANIFOLD AND THREE WAY CATALYST"

 .

Terminal No.

Resistance

2 and 3

3.3 - 4.0 

Ω

 [at 25

°

C (77

°

F)]

1 and 2, 3, 4

∞

 

Ω

(Continuity should not exist)

4 and 1, 2, 3

SEF249Y