P2A00
2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2A00,P2A03: A/F Sensor Circuit Slow Response (Bank 1 Sensor 1)
P2A03 - A/F Sensor Circuit Slow Response (Bank 2 Sensor 1)
CAUTION / NOTICE / HINT
HINT
- DTC P2A00 indicates malfunctions related to the bank 1 air fuel ratio sensor.
- DTC P2A03 indicates malfunctions related to the bank 2 air fuel ratio sensor.
- Bank 1 refers to the bank that includes cylinder No. 1.
- Bank 2 refers to the bank that includes cylinder No. 2.
- 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 P2195.
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 ratio control is performed for approximately 10 seconds after preconditions are met in order to measure the air fuel ratio sensor response rate. During active air fuel ratio ratio control, the ECM forcibly increases and decreases the injection volume to 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 ratio 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 less than the threshold, the ECM interprets this as a malfunction and sets the DTC.
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 on (IG).
3. Turn the tester on.
4. Clear the DTCs (where set).
5. Select the following menu items: Powertrain / Engine and ECT / Monitor / O2 Sensor / Details.
6. Check that RES RATE B1S1 and RES RATE B2S1 are Incomplete.
7. Start the engine and warm it up (Procedure "A").
8. Drive the vehicle at between 25 mph and 75 mph (40 km/h and 120 km/h) for 3 minutes. However, the vehicle should be driven at a constant speed (Procedure "B").
9. Check the monitor result values on the Techstream by selecting the following menu items: Powertrain / Engine and ECT / Monitor / O2 Sensor / Details / RES RATE B1S1 and RES RATE B2S1.
10. If the values indicated on the tester do not change, perform READINESS MONITOR DRIVE PATTERN for the air fuel ratio sensor and the heated oxygen sensor Monitors, Trips, Drive Cycles and Readiness Codes.
HINT
Completion of all air fuel ratio sensor monitors is required to change the value in test result.
11. Note the value of the Monitor Result.
12. Select the following menu items: Powertrain / Engine and ECT / Trouble Code / Pending.
13. Check if any DTCs (any pending DTCs) are set.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
MONITOR RESULT
Refer to CHECKING MONITOR STATUS Mode 6 Data.
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 and turn the tester on.
c. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
d. Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
e. 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).
f. 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.
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.
Standard voltage:
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, select the following menu items on the tester: Control the Injection Volume for A/F Sensor / A/F Control System / AFS B1 S1 or AFS B2 S1 and O2S B1 S2 or O2S B2 S2. Then press the graph button on the Data List view.
HINT
- 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.
- 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.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00 AND/OR P2A03)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch on (IG).
(c) Turn the tester on.
(d) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.
(e) Read the DTCs.
Result:
HINT
If any DTCs other than P2A00 or P2A03 are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART Engine Control System - SFI System
A -- Continue to next step.
2. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
(a) Disconnect the air fuel ratio sensor connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
Bank 1
Bank 2
Text in Illustration
(c) Reconnect the air fuel ratio sensor connector.
NG -- REPLACE AIR FUEL RATIO SENSOR Components
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
(a) Disconnect the air fuel ratio sensor connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Bank 1
Bank 2
Standard resistance (Check for short):
Bank 1
Bank 2
(d) Reconnect the ECM connector.
(e) Reconnect the air fuel ratio sensor connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
OK -- Continue to next step.
4. PERFORM CONFIRMATION DRIVING PATTERN
NEXT -- Continue to next step.
5. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 AND/OR P2A03)
(a) Connect the Techstream to the DLC3.
(b) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes / Pending.
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 Components.
NEXT -- Continue to next step.
7. PERFORM CONFIRMATION DRIVING PATTERN
NEXT -- Continue to next step.
8. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 AND/OR P2A03)
(a) Read the DTCs using the Techstream.
(b) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes / Pending.
Result:
B -- REPLACE ECM
A -- END