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P2A00





2ZR-FE ENGINE CONTROL: SFI SYSTEM: P2A00: A/F Sensor Circuit Slow Response (Bank 1 Sensor 1)
P2A00 - A/F Sensor Circuit Slow Response (Bank 1 Sensor 1)

DESCRIPTION

HINT
Refer to DTC P2195 P2195.





MONITOR DESCRIPTION

After engine is warmed up, the ECM performs air fuel ratio feedback control to maintain the air fuel ratio at the stoichiometric level. In addition, active A/F control is performed for approximately 15 to 20 seconds after preconditions are met in order to measure the air fuel ratio sensor response rate. During active A/F control, the ECM forcibly increases and decreases the injection volume a certain amount, based on the stoichiometric air fuel ratio learned during normal air fuel ratio control, and measures the air fuel ratio sensor response rate. The ECM receives a signal from the air fuel ratio sensor while performing active A/F control and uses it to calculate the air fuel ratio sensor response rate deterioration level.

If the value for air fuel ratio sensor response rate deterioration level is beyond the threshold, the ECM interprets this as a malfunction and sets the DTC.





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





MONITOR RESULT

Refer to Checking Monitor Status Mode 6 Data.

CONFIRMATION DRIVING PATTERN

HINT
Performing this confirmation driving pattern will activate the air fuel ratio sensor response monitor.





1. Connect the Techstream to the DLC3.

2. Turn the ignition switch to ON.

3. Turn the Techstream on.

4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation) Reading and Clearing Diagnostic Trouble Codes.

5. Turn the ignition switch off and wait for at least 30 seconds.

6. Turn the ignition switch to ON and turn the Techstream on.

7. Enter the following menus: Powertrain / Engine and ECT / Monitor / Current Monitor / O2 Sensor / Details.

8. Check that RES RATE B1S1 is Incomplete.

9. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher [A].

10. Drive the vehicle at approximately 37 mph (60 km/h) for 10 minutes or more in a city area [B].

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.

11. Check the monitor result values on the Techstream by entering the following menus: Powertrain / Engine and ECT / Monitor / Current Monitor / O2 Sensor / Details / RES RATE B1S1.

12. If the values indicated on the Techstream do not change, perform Readiness Monitor Drive Pattern for the air fuel ratio sensor and heated oxygen sensor Monitors, Trips, Drive Cycles and Readiness Codes.

13. Note the value of Monitor Result.

14. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].

15. Read the pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

16. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

17. Input the DTC: P2A00.

18. Check the DTC judgment result.





HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or UNKNOWN, perform the following procedure.

19. Drive the vehicle at a speed between 47 and 63 mph (75 and 100 km/h) for 10 minutes [D].

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.

20. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].

21. Read the pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

22. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

23. Input the DTC: P2A00.

24. Check the DTC judgment result.





HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.

25. If the judgment result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P2195 P2195.

INSPECTION PROCEDURE

HINT
Malfunctioning areas can be identified by performing the Control the Injection Volume for A/F Sensor function provided in the Active Test. The Control the Injection Volume for A/F Sensor function can help to determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume for A/F Sensor operation using the Techstream.

(a) Connect the Techstream to the DLC3.
(b) Start the engine.
(c) Turn the Techstream on.
(d) Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
(e) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
(f) Perform the Active Test operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume.)
(g) Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the Techstream.

HINT
- The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
- Each sensor reacts in accordance with increases and decreases in the fuel injection volume.





NOTICE:
The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.





- Following the Control the Injection Volume for A/F Sensor procedure enables technicians to check and graph the voltage outputs of both the air fuel ratio and heated oxygen sensors.

- To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / Data List / All Data / AFS Voltage B1S1 and O2S B1S2; then press the graph button on the Data List view.

HINT
- DTC P2A00 may be also set, when the air fuel ratio is stuck rich or lean.
- A low air fuel ratio sensor voltage could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich.
- A high air fuel ratio sensor voltage could be caused by a lean air fuel mixture. Check for conditions that would cause the engine to run lean.
- Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
- Sensor 1 refers to the sensor closest to the engine assembly.
- Sensor 2 refers to the sensor farthest away from the engine assembly.

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Read the DTCs.

Result:





HINT
If any DTCs other than P2A00 are output, troubleshoot those DTCs first.

B -- GO TO DTC CHART SFI System
A -- Continue to next step.

2. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) P0031

NG -- REPLACE AIR FUEL RATIO SENSOR Removal
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM) P2237

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
OK -- Continue to next step.

4. PERFORM CONFIRMATION DRIVING PATTERN

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON and turn the Techstream on.

(g) Start the engine and warm it up.

(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

NEXT -- Continue to next step.

5. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)

(a) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

(b) Input the DTC P2A00.

(c) Check the DTC judgment result.

Result:





B -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
A -- Continue to next step.

6. REPLACE AIR FUEL RATIO SENSOR

(a) Replace the air fuel ratio sensor Removal.

NEXT -- Continue to next step.

7. PERFORM CONFIRMATION DRIVING PATTERN

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON and turn the Techstream on.

(g) Start the engine and warm it up.

(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

NEXT -- Continue to next step.

8. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)

(a) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

(b) Input the DTC P2A00.

(c) Check the DTC judgment result.

Result:





B -- CHECK ENGINE TO DETERMINE CAUSE OF EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO P0171

A -- END