| DTC Code | DTC Name |
|---|---|
| P2A00 | A/F Sensor Circuit Slow Response (Bank 1 Sensor 1) |
| P2A03 | A/F Sensor Circuit Slow Response (Bank 2 Sensor 1) |
DESCRIPTION
Refer to DTC P2195.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory |
|---|---|---|---|---|---|
| P2A00 | A/F Sensor Circuit Slow Response (Bank 1 Sensor 1) | The calculated value for the air fuel ratio sensor response rate deterioration level is less than the threshold (2 trip detection logic). |
|
Comes on (Euro-OBD) / - (Except Euro-OBD) | DTC stored (Euro-OBD) / - (Except Euro-OBD) |
| P2A03 | A/F Sensor Circuit Slow Response (Bank 2 Sensor 1) | The calculated value for the air fuel ratio sensor response rate deterioration level is less than the threshold (2 trip detection logic). |
|
Comes on (Euro-OBD) / - (Except Euro-OBD) | DTC stored (Euro-OBD) / - (Except Euro-OBD) |
MONITOR DESCRIPTION
After the 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 ratio control is performed for approximately 30 seconds or more after preconditions are met in order to measure the air fuel ratio sensor response rate. During active air fuel ratio control, the ECM forcibly increases and decreases the injection volume by 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 air fuel ratio control and uses it to calculate the air fuel ratio sensor response rate deterioration level.
If the value for the air fuel ratio sensor response rate deterioration level is less than the threshold, the ECM interprets this as a malfunction and stores the DTC.
MONITOR STRATEGY
| Required Sensors/Components | Air fuel ratio sensor |
| Frequency of Operation | Once per driving cycle |
TYPICAL ENABLING CONDITIONS
| Active air fuel ratio control | Performing |
| Active air fuel ratio control performed when following conditions met | - |
| Engine coolant temperature | 75°C (167°F) or higher |
| Idling | Off |
| Engine speed | Less than 4000 rpm |
| Air fuel ratio sensor status | Activated |
| Fuel-cut | Off |
| Engine load | 10% or higher, and less than 70% |
| Shift position | 2nd or more |
| Catalyst monitor | Not yet |
| Mass air flow | 4.0 gm/sec or more, and less than 14 gm/sec |
CONFIRMATION DRIVING PATTERN
Tech Tips
Performing this confirmation pattern will activate the air fuel ratio sensor response monitor.
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) and turn the GTS on.
Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher [A].
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.
Enter the following menus: Powertrain / Engine / Trouble Codes [C].
Read the pending DTCs.
Tech Tips
If a pending DTC is output, the system is malfunctioning.
If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P2A00 or P2A03.
Check the DTC judgment result.
| GTS Display | Description |
|---|---|
| NORMAL |
|
| ABNORMAL |
|
| INCOMPLETE |
|
| N/A |
|
Tech Tips
If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the test result is INCOMPLETE or N/A and no pending DTC is output, perform the following procedure.
Drive the vehicle at a speed between 75 and 100 km/h (47 and 62 mph) for 10 minutes [D].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Enter the following menus: Powertrain / Engine / Trouble Codes [E].
Read the pending DTCs.
Tech Tips
If a pending DTC is output, the system is malfunctioning.
If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P2A00 or P2A03.
Check the DTC judgment result.
| GTS Display | Description |
|---|---|
| NORMAL |
|
| ABNORMAL |
|
| INCOMPLETE |
|
| N/A |
|
Tech Tips
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, drive the vehicle again under an increased load and then recheck the judgment result.
CAUTION / NOTICE / HINT
Note
Inspect the fuses for circuits related to this system before performing the following procedure.
Tech Tips
DTC P2A00 or P2A03 may be also stored when the air fuel ratio is stuck at 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.
Bank 1 refers to the bank that includes the No. 1 cylinder*.
*: The No. 1 cylinder is the cylinder which is farthest from the transmission.
Bank 2 refers to the bank that does not include the No. 1 cylinder.
Sensor 1 refers to the sensor closest to the engine assembly.
Sensor 2 refers to the sensor farthest away from the engine assembly.
Read freeze frame data using the GTS. 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
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00 OR P2A03)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Read the DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
Tech Tips
If any DTCs other than P2A00 or P2A03 are output, troubleshoot those DTCs first.
| B |
|
GO TO DTC CHART Click here |
| A |
|
PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)
Connect the GTS to the DLC3.
Start the engine.
Turn the GTS on.
Warm up the engine and run the engine at an engine speed of 2500 rpm for approximately 90 seconds.
Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor / All Data / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.
| Active Test Display |
|---|
| Control the Injection Volume for A/F Sensor |
| Data List Display |
|---|
| AFS Voltage B1S1 |
| AFS Voltage B2S1 |
| O2S B1S2 |
| O2S B2S2 |
Perform the Control the Injection Volume for A/F Sensor operation with the engine idling.
Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the GTS.
Tech Tips
The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 12.5%.
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.
| GTS Display (Sensor) | Injection Volume | Status | Voltage |
|---|---|---|---|
| AFS Voltage B1S1 AFS Voltage B2S1 (Air fuel ratio) |
12.5% | Rich | Below 3.1 V |
| -12.5% | Lean | Higher than 3.4 V | |
| O2S B1S2 O2S B2S2 (Heated oxygen) |
12.5% | Rich | Higher than 0.55 V |
| -12.5% | Lean | Below 0.4 V |
| Result | ||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor output voltages (AFS Voltage B1S1 and AFS Voltage B2S1) are consistently higher than 3.4 V, and the heated oxygen sensor output voltages (O2S B1S2 and O2S B2S2) are consistently below 0.4 V.
Rich: During the Control the Injection Volume for A/F Sensor Active Test, the AFS Voltage B1S1 and AFS Voltage B2S1 are consistently below 3.1 V, and the O2S B1S2 and O2S B2S2 are consistently higher than 0.55 V.
Lean/Rich: During the Control the Injection Volume for A/F Sensor Active Test, the output voltage of the air fuel ratio sensor or heated oxygen sensor alternates correctly.
Tech Tips
Refer to "Data List / Active Test" [AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2].
| B |
|
INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) Click here |
| C |
|
GO TO STEP 10 Click here |
| A |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 OR P2A03)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG).
Turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
| Tester Display |
|---|
| All Readiness |
Input the DTC: P2A00 or P2A03.
Check the DTC judgment result.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| A |
|
CHECK FOR INTERMITTENT PROBLEMS Click here |
| B |
|
GO TO STEP 10 Click here |
INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
Inspect the air fuel ratio sensor.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE AIR FUEL RATIO SENSOR Click here |
| OK |
|
CHECK INTAKE SYSTEM
Check the intake system for vacuum leaks.
| OK |
|---|
| No leaks in the intake system. |
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE INTAKE SYSTEM |
| OK |
|
CHECK FUEL PRESSURE (FOR LOW PRESSURE SIDE)
Check the fuel pressure (for low pressure side).
| Result | |||
|---|---|---|---|
|
| NG |
|
INSPECT FUEL PUMP (FOR LOW PRESSURE SIDE) Click here |
| OK |
|
INSPECT FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION)
Inspect the fuel injector assembly (for port injection) (whether fuel volume is high or low, and whether injection pattern is poor).
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION) Click here |
| OK |
|
CHECK FUEL PRESSURE (FOR HIGH PRESSURE SIDE)
Check the fuel pressure (for high pressure side).
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE FUEL SYSTEM (FOR HIGH PRESSURE SIDE) |
| OK |
|
INSPECT FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION)
Inspect the fuel injector assembly (for direct injection).
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION) Click here |
| OK |
|
REPLACE AIR FUEL RATIO SENSOR
Replace the air fuel ratio sensor.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 OR P2A03)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG).
Turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
| Tester Display |
|---|
| All Readiness |
Input the DTC: P2A00 or P2A03.
Check the DTC judgment result.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
END |
| A |
|
REPLACE ECM
Replace the ECM.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 OR P2A03)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG).
Turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
| Tester Display |
|---|
| All Readiness |
Input the DTC: P2A00 or P2A03.
Check that the DTC judgment result is NORMAL.
| Result | ||
|---|---|---|
|
| NEXT |
|
END |
INSPECT FUEL PUMP (FOR LOW PRESSURE SIDE)
Inspect the fuel pump (for low pressure side).
| Result | |||
|---|---|---|---|
|
| OK |
|
REPAIR OR REPLACE FUEL LINE |
| NG |
|
REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE) Click here |