Infiniti Q45. Manual - part 385

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER

EC-179

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5. 

CHECK A/F SENSOR 1 HEATER

Refer to 

EC-179, "Component Inspection"

 .

OK or NG

OK

>> GO TO 6.

NG

>> Replace malfunctioning air fuel ratio sensor 1.

6. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-145, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Component Inspection

NBS002WW

AIR FUEL RATIO (A/F) SENSOR 1 HEATER

Check resistance between terminals 3 and 4.

Check continuity between terminals 3 and 1, 2, 5, 6, terminals 4 and
1, 2, 5, 6.

If NG, replace the A/F sensor 1.

CAUTION:

●

Discard any 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 A/F sensor, clean exhaust system
threads using Heated Oxygen Sensor Thread Cleaner tool
J-43897-18 or J-43897-12 and approved anti-seize lubricant.

Removal and Installation 

NBS002WX

AIR FUEL RATIO (A/F) SENSOR 1

Refer to 

EM-23, "EXHAUST MANIFOLD AND THREE WAY CATALYST"

 .

Resistance: 2.3 - 4.3

Ω

 [at 25

°

C (77

°

F)]

Continuity should not exist.

PBIB1684E

EC-180

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER

PFP:226A0

Description

NBS001S7

SYSTEM DESCRIPTION

The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature. 

OPERATION

CONSULT-II Reference Value in Data Monitor Mode

NBS001S8

Specification data are reference values.

On Board Diagnosis Logic

NBS001S9

Sensor

Input Signal to ECM

ECM function

Actuator

Camshaft position sensor (PHASE)

Engine speed

Heated oxygen sensor 2 
heater control

Heated oxygen sensor 2 heater

Crankshaft position sensor (POS)

Engine coolant temperature sensor

Engine coolant temperature

Mass air flow sensor

Amount of intake air

Engine speed rpm

Heated oxygen sensor 2 heater

Above 3,600

OFF

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

MONITOR ITEM

CONDITION

SPECIFICATION

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

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0037
0037
(Bank 1)

Heated oxygen sensor 2 
heater control circuit low

The current amperage in the heated oxygen sensor 
2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM 
through the heated oxygen sensor 2 heater.)

●

Harness or connectors
(The heated oxygen sensor 2 heater 
circuit is open or shorted.)

●

Heater oxygen sensor 2 heater

P0057
0057
(Bank 2)

P0038
0038
(Bank 1)

Heated oxygen sensor 2 
heater control circuit high

The current amperage in the heated oxygen sensor 
2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM 
through the heated oxygen sensor 2 heater.)

●

Harness or connectors
(The heated oxygen sensor 2 heater 
circuit is shorted.)

●

Heater oxygen sensor 2 heater

P0058
0058
(Bank 2)

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER

EC-181

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EC

DTC Confirmation Procedure

NBS001SA

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at
idle.

 WITH CONSULT-II

1.

Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.

2.

Start the 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.

5.

Let engine idle for 1 minute.

6.

If 1st trip DTC is detected, go to 

EC-185, "Diagnostic Procedure"

.

 WITH GST

Follow the procedure “WITH CONSULT-II” above.

SEF174Y

EC-182

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER

Wiring Diagram

NBS001SB

BANK 1

TBWM1221E