P2A00
2ZR-FE ENGINE CONTROL SYSTEM: 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
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 air fuel control is performed for approximately 10 seconds after preconditions are met in order to measure the Air Fuel Ratio (A/F) 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 A/F sensor response rate. The ECM receives a signal from the A/F sensor while performing active A/F control and uses it to calculate the A/F sensor response rate deterioration level.
If the value for A/F sensor response rate deterioration level is less than the threshold, the ECM interprets this as a malfunction and stores 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 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 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.
8. Check that O2 Sensor / Current 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 60 km/h (37 mph) 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 Test Result.
14. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
15. Read 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 N/A, perform the following procedure.
19. Drive the vehicle at a speed between 75 and 100 km/h (47 and 63 mph) 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 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 N/A 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
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT
- DTC P2A00 may be also stored, when the air fuel ratio is stuck rich or lean.
- Sensor 1 refers to the sensor closest to the engine assembly.
- Sensor 2 refers to the sensor farthest away from the engine assembly.
- A low A/F sensor voltage could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich.
- A high A/F 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 help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
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 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. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME)
(a) Connect the Techstream to the DLC3.
(b) Start the engine.
(c) Turn the Techstream on.
(d) Warm up the engine and run 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.
(f) Perform the Control the Injection Volume operation with the engine idling.
(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
- Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations.
- 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.
- If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.
Result
Lean: During the Control the Injection Volume Active Test, the A/F sensor output voltage (AFS Voltage B1S1) is consistently higher than 3.4 V, and the HO2 sensor output voltage (O2S B1S2) is consistently below 0.4 V.
Rich: During the Control the Injection Volume Active Test, the AFS Voltage B1S1 is consistently below 3.1 V, and the O2S B1S2 is consistently higher than 0.55 V.
Lean/Rich: During the Control the Injection Volume Active Test, the output voltage of the HO2 sensor alternates correctly.
HINT
Refer to "Data List / Active Test" [AFS Voltage B1S1, O2S B1S2] Data List / Active List.
B -- INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
C -- REPLACE AIR FUEL RATIO SENSOR
A -- Continue to next step.
3. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)
(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.
(g) Turn the Techstream on.
(h) Start the engine and warm it up.
(i) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(j) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(k) Input the DTC: P2A00.
(l) Check the DTC judgment result.
Result
B -- REPLACE AIR FUEL RATIO SENSOR
A -- CHECK FOR INTERMITTENT PROBLEMS Check For Intermittent Problems
4. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) P0031
NG -- REPLACE AIR FUEL RATIO SENSOR Removal
OK -- Continue to next step.
5. CHECK INTAKE SYSTEM
(a) Check the intake system Intake System.
NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.
6. CHECK FUEL PRESSURE
(a) Check the fuel pressure Fuel System.
NG -- INSPECT FUEL PUMP
OK -- Continue to next step.
7. CHECK FUEL INJECTOR
(a) Inspect the fuel injector Testing and Inspection.
NG -- REPLACE FUEL INJECTOR
OK -- Continue to next step.
8. REPLACE AIR FUEL RATIO SENSOR
(a) Replace the air fuel ratio sensor Removal.
NEXT -- Continue to next step.
9. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)
(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.
(g) Turn the Techstream on.
(h) Start the engine and warm it up.
(i) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(j) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(k) Input the DTC: P2A00.
(l) Check the DTC judgment result.
Result
B -- END
A -- Continue to next step.
10. REPLACE ECM
(a) Replace the ECM Removal.
NEXT -- Continue to next step.
11. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)
(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.
(g) Turn the Techstream on.
(h) Start the engine and warm it up.
(i) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(j) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(k) Input the DTC: P2A00.
(l) Check that the DTC judgment result is NORMAL.
NEXT -- END
12. INSPECT FUEL PUMP
(a) Inspect the fuel pump Inspection.
NG -- REPLACE FUEL PUMP
OK -- REPAIR OR REPLACE FUEL LINE