Troubleshooting
DTC P2A00 A/F SENSOR CIRCUIT SLOW RESPONSE (BANK 1 SENSOR 1)CIRCUIT DESCRIPTION
DTC Detecting Condition:
A thermistor built in the water temperature sensor changes the resistance value according to the water temperature.
The structure of the sensor and connection to the ECM is the same as the those of the air temperature sensor.
HINT:
- P2A00 means malfunction of bank 1 A/F sensor circuit.
- P2A03 means malfunction of bank 2 A/F sensor circuit.
- 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 closest to the engine body.
CONFIRMATION DRIVING PATTERN
1. Connect the hand-held tester to the DLC3. (*1)
2. Switch the hand-held tester from the normal mode to the check mode. (*1)
3. Start the engine and warm it up with all the accessory switches OFF. (*2)
4. Drive the vehicle at 60 - 120 km/h (38 - 75 mph) and engine speed at 1,400 - 3,200 rpm for 3 - 5 min. (*3)
HINT: If a malfunction exists, the MIL will light up during step (*3).
NOTE: If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.
If you do not have a hand-held tester, turn the ignition switch OFF after performing steps (*2) and (*3), then perform steps (*2) and (*3) again.
Wiring Diagram:
Step 1 - 2:
Step 2 (continued):
Step 3 - 4:
Step 5:
Step 6 - 10:
Step 11 - 18:
INSPECTION PROCEDURE
HINT:
- This diagnostics procedure is designed to work for both P2A00 and P2A03.
- The A/F sensor signal must be checked using the hand-held tester or OBD II scan tool.
- DTC P2A00 or P2A03 may be also detected, when the air fuel ratio is stuck rich or lean.
- Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when the malfunction is detected. When troubleshooting, this is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.
CHECK FOR INTERMITTENT PROBLEMS
Hand-held tester only:
By putting the vehicle's ECM in the check mode, the 1 trip detection logic is possible instead of the 2 trip detection logic and the sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
1. Clear the DTCs.
2. Set the check mode.
3. Perform a simulation test.
4. Check the connector and terminal.
5. Handle the connector.