P2A00

DTC P2A00, P2A03 A/F SENSOR 1

Component Description

The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sensor. The sensor element of the A/F sensor 1 is the combination of a
Nearmst 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 < The exhaust gas components diffuse through the diffusion gap at the electrode of the oxygen pump and Nermst 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 temperature of 700 - 800�C (1,292 - 1,472�F).

CONSULT-III Reference Value in Data Monitor Mode
Specification data are reference values.

On Board Diagnosis Logic
To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to shift to LEAN side or RICH side.

DTC DETECTION LOGIC:

DTC Confirmation Procedure

NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.

WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON and select "SELF-LEARNING CONT" in "WORK SUPPORT" mode with CONSULT-III.
6. Clear the self-learning coefficient by touching "CLEAR".
7. Turn ignition switch OFF and wait at least 10 seconds.
8. Turn ignition switch ON.
9. Turn ignition switch OFF and wait at least 10 seconds.
10. Start engine and keep the engine speed between 3,500 and 4,000 rpm for 1 minute under no load.
11. Let engine idle for 1 minute.
12. Keep engine speed between 2,500 and 3,000 rpm for 20 minutes.
13. Check 1st trip DTC.
14. If 1st trip DTC is detected, go to P2A00.

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 connector.
6. Turn ignition switch ON.
7. Select Service $03 with GST and check that DTC P0102 is detected.
8. Select Service $04 with GST and erase the DTC P0102.
9. Turn ignition switch OFF and wait at least 10 seconds.
10. Turn ignition switch ON.
11. Turn ignition switch OFF and wait at least 10 seconds.
12. Start engine and keep the engine speed between 3,500 and 4,000 rpm for 1 minute under no load.
13. Let engine idle for 1 minute.
14. Keep engine speed between 2,500 and 3,000 rpm for 20 minutes.
15. Check 1st trip DTC.
16. If 1st trip DTC is detected, go to P2A00.

Wiring Diagram

BANK 1

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

CAUTION:
Never use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

BANK 2

Diagnosis Procedure
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body. Refer to Power Supply and Ground Circuit.

OK or NG
OK - GO TO 2.
NG - Repair or replace ground connections.
2.RETIGHTEN AIR FUEL RATIO (A/F) SENSOR 1
1. Loosen and retighten the air fuel ratio (A/F) sensor 1.

Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)

GO TO 3.
3.CHECK FOR INTAKE AIR LEAKAGE
1. Start engine and run it at idle.
2. Listen for an intake air leakage after the mass air flow sensor.
OK or NG
OK - GO TO 4.
NG - Repair or replace malfunctioning part.
4.CLEAR THE SELF-LEARNING DATA
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select "SELF-LEARNING CONT" in "WORK SUPPORT" mode with CONSULT-III.
3. Clear the self-learning control coefficient by touching "CLEAR".
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.

3. Disconnect mass air flow sensor (1) harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness connector.
6. Check that DTC P0102 is displayed.
7. Erase the DTC memory. Refer to "How to Erase DTC" in Emission-Related Diagnostic Information.
8. Check that DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Yes or No
Yes - Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to P0171 or P0172.
No - GO TO 5.
5.CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.

3. Check harness connector for water.

Water should not exit.

OK or NG
OK - GO TO 6.
NG - Repair or replace harness connector.
6.CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.

2. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-III or tester.

Voltage: Battery voltage

OK or NG
OK - GO TO 8.
NG - GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E12, F3
- IPDM E/R harness connector E7
- 15 A fuse
- Harness for open or short between A/F sensor 1 and fuse
Repair or replace harness or connectors.
8.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as per the following. Refer to Wiring Diagram.

Continuity should exist

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

Continuity should exist.

5. Also check harness for short to power.
OK or NG
OK - GO TO 9.
NG - Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK A/F SENSOR 1 HEATER
Refer to P0031.
OK or NG
OK - GO TO 10.
NG - GO TO 11.
10.CHECK INTERMITTENT INCIDENT
Perform Diagnosis Procedure.
OK or NG
OK - GO TO 11.
NG - Repair or replace malfunctioning part.
11.REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air fuel ratio (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 Oxygen Sensor Thread
Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved Anti-seize Lubricant
(commercial service tool).
GO TO 12.
12.CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch ON.
2. Select "A/F ADJ-B1" and "A/F ADJ-B2" in "DATA MONITOR" mode with CONSULT-III.
3. Check that that "0.000" is displayed on CONSULT-III screen.
OK or NG
OK INSPECTION END
NG - GO TO 13.
13.CLEAR A/F ADJUSTMENT DATA
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select "SELF-LEARNING CONT" in "WORK SUPPORT" mode with CONSULT-III.
3. Clear the self-learning control coefficient by touching "CLEAR".
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.

3. Disconnect mass air flow sensor (1) harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness connector.
6. Check that DTC P0102 is displayed.
7. Erase the DTC memory. Refer to "How to Erase DTC" in Emission-Related Diagnostic Information.
8. Check that DTC P0000 is displayed.
GO TO 14.
14.CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch OFF and then ON.
2. Select "A/F ADJ-B1" and "A/F ADJ-B2" in "DATA MONITOR" mode with CONSULT-III.
3. Check that that "0.000" is displayed on CONSULT-III screen.
INSPECTION END

Removal and Installation

AIR FUEL RATIO (A/F) SENSOR 1
Refer to Component.