Infiniti FX35 / FX45. Manual - part 592

DTC P2A00, P2A03 A/F SENSOR 1

EC-1129

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DTC P2A00, P2A03 A/F SENSOR 1

Component Description

INFOID:0000000001327032

The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement   = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide   range (0.7 <

 < air).

The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.

An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at   = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800

°

C (1,292 - 1,472

°

F).

CONSULT-III Reference Value in Data Monitor Mode

INFOID:0000000001327033

Specification data are reference values.

On Board Diagnosis Logic

INFOID:0000000001327034

To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be
shifted to LEAN side or RICH side.

DTC Confirmation Procedure

INFOID:0000000001327035

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 more than 11V at idle.

 WITH CONSULT-III

1.

Start engine and warm it up to normal operating temperature.

SEF579Z

SEF580Z

MONITOR ITEM

CONDITION

SPECIFICATION

A/F SEN1 (B1)
A/F SEN1 (B2)

• Engine: After warming up

Maintaining engine speed at 2,000 rpm

Fluctuates around 1.5 V

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible Cause

P2A00
2A00
(Bank 1)

Air fuel ratio (A/F) sensor 1 
circuit range/performance

• The output voltage computed by ECM from the 

A/F sensor 1 signal is shifted to the lean side for 
a specified period.

• The A/F signal computed by ECM from the A/F 

sensor 1 signal is shifted to the rich side for a 
specified period.

• A/F sensor 1
• A/F sensor 1 heater
• Fuel pressure
• Fuel injector
• Intake air leaks

P2A03
2A03
(Bank 2)

EC-1130

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DTC P2A00, P2A03 A/F SENSOR 1

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-III.

4.

Clear the self-learning coefficient by touching “CLEAR”.

5.

Turn ignition switch OFF and wait at least 10 seconds.

6.

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

7.

Let engine idle for 1 minute.

8.

Keep engine speed between 2,500 and 3,000 rpm for 20 minutes.

9.

Check 1st trip DTC.

10. If 1st trip DTC is detected, go to 

EC-1134, "Diagnosis Procedure"

.

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Disconnect mass air flow sensor (1) harness connector.

4.

Start engine and let it idle for at least 5 seconds.

5.

Stop engine and reconnect mass air flow sensor harness con-
nector.

6.

Select Service $03 with GST and make sure that DTC P0102 is
detected.

7.

Select Service $04 with GST and erase the DTC P0102.

8.

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

9.

Let engine idle for 1 minute.

10. Keep engine speed between 2,500 and 3,000 rpm for 20 min-

utes.

11. Check 1st trip DTC.

12. If 1st trip DTC is detected, go to 

EC-1134, "Diagnosis Procedure"

.

PBIB3230E

DTC P2A00, P2A03 A/F SENSOR 1

EC-1131

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Wiring Diagram

INFOID:0000000001327036

BANK 1

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

CAUTION:

TBWM1373E

EC-1132

< SERVICE INFORMATION >

[VK45DE]

DTC P2A00, P2A03 A/F SENSOR 1

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.)

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

2

P

A/F sensor 1 heater
(Bank 1)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 5V

16

R

A/F sensor 1 (Bank 1)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 3.1V

35

G

Approximately 2.6V

56

B

Approximately 2.3V

75

OR

Approximately 2.3V

PBIB1584E