Infiniti Q45. Manual - part 386

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER

EC-183

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)

6

GY

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)

55

PU

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

–

After 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

OR

Sensor ground
(Heated oxygen sensor 2)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 0V

EC-184

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER

BANK 2

TBWM1222E

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER

EC-185

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

NBS001SC

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

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

EC-154, "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)

25

G

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)

74

B

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

–

After 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

OR

Sensor ground
(Heated oxygen sensor 2)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 0V

PBIB2417E

EC-186

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER

2. 

CHECK HO2S2 POWER SUPPLY CIRCUIT

1.

Disconnect heated oxygen sensor 2 harness connector.

2.

Turn ignition switch ON.

3.

Check voltage between HO2S2 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 B11, E211

●

Harness connectors E35, E305

●

Fuse block (J/B) No.1 connector B1

●

10A fuse

●

Harness for open or short between heated oxygen sensor 2 and fuse

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

4. 

CHECK HO2S2 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 HO2S2 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 6.

NG

>> GO TO 5.

Voltage: Battery voltage

PBIB0018E

PBIB0112E

DTC

Terminals

Bank

ECM

Sensor

P0037, P0038

6

2

1

P0057, P0058

25

2

2

Continuity should exist.