SFI SYSTEM, Diagnostic DTC:P2A00, P2A03
| 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) |
CAUTION / NOTICE / HINT
Tech Tips
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DTC P2A00 indicates malfunctions related to the bank 1 air fuel ratio sensor.
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DTC P2A03 indicates malfunctions related to the bank 2 air fuel ratio sensor.
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Bank 1 refers to the bank that includes cylinder No. 1.
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Bank 2 refers to the bank that includes cylinder No. 2.
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Sensor 1 refers to the sensor mounted in front of the three-way catalytic converter and located near the engine assembly.
DESCRIPTION
Refer to DTC P2195 Click here.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2A00 P2A03 |
Calculated value for air fuel ratio sensor response rate deterioration level is less than threshold |
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CONFIRMATION DRIVING PATTERN
Tech Tips
Performing this confirmation driving pattern will activate the air fuel ratio sensor response monitor.
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Connect the intelligent tester to the DLC3 (Procedure "A").
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Turn the ignition switch on (IG) (Procedure "B").
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Turn the tester on (Procedure "C").
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Clear the DTCs (where set) (Procedure "D").
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Start the engine and warm it up (Procedure "E").
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Drive the vehicle at between 60 km/h and 120 km/h (38 mph and 75 mph) for 3 minutes. However, the vehicle should be driven at a constant speed (Procedure "F").
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Select the following menu items: Powertrain / Engine and ECT / DTC (Procedure "G").
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Check if any DTCs (any pending DTCs) are set (Procedure "H").
WIRING DIAGRAM
Refer to DTC P2195 Click here.
INSPECTION PROCEDURE
Tech Tips
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.
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The following instructions describe how to conduct the Control the Injection Volume for A/F Sensor operation using an intelligent tester.
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Connect the intelligent tester to the DLC3.
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Start the engine and turn the tester on.
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Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
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Select the following menu items on the tester: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
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Perform the Control the Injection Volume for A/F Sensor operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).
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Monitor the voltage outputs of the air fuel ratio and heated oxygen sensors (AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2) displayed on the tester.
Tech Tips
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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%.
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Each sensor reacts in accordance with increases and decreases in the fuel injection volume.
Standard voltage Tester Display (Sensor) Injection Volume Status Voltage AFS B1S1 or AFS B2S1 (Air fuel ratio) +25% Rich Less than 3.0 AFS B1S1 or AFS B2S1 (Air fuel ratio) -12.5% Lean More than 3.35 O2S B1S2 or O2S B2S2 (Heated oxygen) +25% Rich More than 0.55 O2S B1S2 or O2S B2S2 (Heated oxygen) -12.5% Lean Less than 0.4 Note
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.
Case Air Fuel Ratio Sensor (Sensor 1)
Output Voltage
Heated Oxygen Sensor (Sensor 2)
Output Voltage
Main Suspected Trouble Area 1 
- 2 
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Air fuel ratio sensor
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Air fuel ratio sensor heater
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Air fuel ratio sensor circuit
3
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Heated oxygen sensor
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Heated oxygen sensor heater
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Heated oxygen sensor circuit
4
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Fuel pressure
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Gas leakage from exhaust system
(Air fuel ratio extremely lean or rich)
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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.
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The following air fuel ratio control procedure enables the technician to check and graph the voltage output of both the heated oxygen sensors. To display the graph, select the following menu items on the tester: View / Line Graph.
Tech Tips
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DTC P2A00 or P2A03 may be also set when the air fuel ratio is stuck rich or lean.
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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.
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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.
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Read freeze frame data using the intelligent tester. 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.
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PROCEDURE
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CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00 AND/OR P2A03)
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Connect the intelligent tester to the DLC3.
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Turn the ignition switch on (IG).
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Turn the tester on.
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Select the following menu items: Powertrain / Engine and ECT / DTC.
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Read the DTCs.
Result Display (DTC Output) Proceed to P2A00 and/or P2A03 A P2A00 and/or P2A03 and other DTCs B Tech Tips
If any DTCs other than P2A00 or P2A03 are output, troubleshoot those DTCs first.
B 
GO TO DTC CHART Click here
A 
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INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
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Disconnect the air fuel ratio sensor connector.
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Measure the resistance according to the value(s) in the table below.
Standard resistance Bank 1 Tester Connection Condition Specified Condition B20-1 (HA1A) - B20-2 (+B) 20°C (68°F) 1.8 to 3.4 Ω B20-1 (HA1A) - B20-4 (A1A-) Always 10 kΩ or higher Bank 2 Tester Connection Condition Specified Condition B19-1 (HA2A) - B19-2 (+B) 20°C (68°F) 1.8 to 3.4 Ω B19-1 (HA2A) - B19-4 (A2A-) Always 10 kΩ or higher -
Reconnect the air fuel ratio sensor connector.
NG
REPLACE AIR FUEL RATIO SENSOR Click here
OK
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CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
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Disconnect the air fuel ratio sensor connector.
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Disconnect the ECM connector.
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Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open) Bank 1 Tester Connection Condition Specified Condition B20-3 (A1A+) - B2-22 (A1A+) Always Below 1 Ω B20-4 (A1A-) - B2-30 (A1A-) Always Below 1 Ω Bank 2 Tester Connection Condition Specified Condition B19-3 (A2A+) - B2-23 (A2A+) Always Below 1 Ω B19-4 (A2A-) - B2-31 (A2A-) Always Below 1 Ω Standard resistance (Check for short) Bank 1 Tester Connection Condition Specified Condition B20-3 (A1A+) or B2-22 (A1A+) - Body ground Always 10 kΩ or higher B20-4 (A1A-) or B2-30 (A1A-) - Body ground Always 10 kΩ or higher Bank 2 Tester Connection Condition Specified Condition B19-3 (A2A+) or B2-23 (A2A+) - Body ground Always 10 kΩ or higher B19-4 (A2A-) or B2-31 (A2A-) - Body ground Always 10 kΩ or higher -
Reconnect the ECM connector.
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Reconnect the air fuel ratio sensor connector.
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
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PERFORM CONFIRMATION DRIVING PATTERN
NEXT
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CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 AND/OR P2A03)
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Read the DTCs using the intelligent tester.
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Select the following menu items: Powertrain / Engine and ECT / DTC.
Result Display (DTC Output) Proceed to P2A00 and/or P2A03 A No output B
B
CHECK FOR INTERMITTENT PROBLEMS Click here
A
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REPLACE AIR FUEL RATIO SENSOR
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Replace the air fuel ratio sensor Click here.
NEXT
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PERFORM CONFIRMATION DRIVING PATTERN
NEXT
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CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 AND/OR P2A03)
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Read the DTCs using the intelligent tester.
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Select the following menu items: Powertrain Engine and ECT / DTC.
Result Display (DTC Output) Proceed to No output A P2A00 and/or P2A03 B
B
CHECK EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO (REFER TO DTC P0171 PROCEDURE) Click here
A 
END
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