P2A03
DTC P2A03 A/F SENSOR CIRCUIT SLOW RESPONSE (BANK 2 SENSOR 1)HINT:
- DTC P2A00 is a malfunction related to the bank 1 A/F sensor.
- DTC P2A03 is a malfunction related to the bank 2 A/F sensor.
DTC Detecting Condition:
CIRCUIT DESCRIPTION
HINT:
- 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 assembly.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions Part 1:
Typical Enabling Conditions Part 2:
Typical Malfunction Thresholds:
The air-fuel ratio (A/F) sensor varies its output voltage in proportion to the air-fuel ratio. Based on the output voltage, the ECM determines if the air-fuel ratio is RICH or LEAN and adjusts the stoichiometric air-fuel ratio. The ECM also checks the fuel injection volume compensation value to check if the A/F sensor is deteriorating or not. The output voltage variation, known as locus length, should be high when the air-fuel ratio fluctuates. When the A/F sensor response rate has deteriorated, the locus length should be short.
The ECM concludes that there is a malfunction in the ratio of the A/F sensor when the locus length is short and the response rate has deteriorated.
MONITOR RESULT
Refer to "Monitors, Trips and/or Drive Cycle" for detailed information.
The test value and test limit information are described as shown in the following table. Check the monitor result and test values after performing the monitor drive pattern.
- TID (Test Identification Data) is assigned to each emission-related component.
- TLT (Test Limit Type):
If TLT is 0, the component is malfunctioning when the test value is higher than the test limit.
If TLT is 1, the component is malfunctioning when the test value is lower than the test limit.
- CID (Component Identification Data) is assigned to each test value.
- Unit Conversion is used to calculate the test value indicated on generic OBD II scan tools.
Wiring Diagram:
Step 1 - 2:
Step 2 (Contd.):
Step 3 - 4:
Step 5:
Step 6 - 11:
Step 12 - 16:
Step 17 - 19:
INSPECTION PROCEDURE
HINT:
Hand-held tester only:
It is possible the malfunctioning area can be found using the ACTIVE TEST A/F CONTROL operation. The A/F CONTROL operation can determine if the A/F sensor, heated oxygen sensor or other potential trouble areas are malfunctioning or not.
a. Perform the ACTIVE TEST A/F CONTROL operation.
HINT: The A/F CONTROL operation lowers the injection volume 12.5% or increases the injection volume 25%.
1. Connect the hand-held tester to the DLC3 on the vehicle.
2. Turn the ignition switch ON.
3. Warm up the engine by running the engine at 2,500 rpm for approximately 90 seconds.
4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
5. Perform the A/F CONTROL operation with the engine idle (press the right or left button).
Result:
A/F sensor reacts in accordance with increase and decrease of injection volume:
+25% --> RICH output: Less than 3.0 V
-12.5% --> LEAN output: More than 3.35 V
Heated oxygen sensor reacts in accordance with increase and decrease of injection volume:
+25% --> RICH output: More than 0.55 V
-12.5% --> LEAN output: Less than 0.4 V
NOTE: The A/F sensor output has a few seconds of delay and the heated oxygen sensor output has about 20 seconds of delay at maximum.
The following A/F CONTROL procedure enables the technician to check and graph the voltage outputs of both the A/F sensor and the heated oxygen sensor.
For displaying the graph, enter "ACTIVE TEST / A/F CONTROL / USER DATA", select "AFS B1S1 and O2S B1S2" by pressing "YES" and push "ENTER". Then press "F4".
HINT:
- DTC P2A00 or P2A03 may be also detected, when the air-fuel ratio is stuck rich or lean.
- 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 with a RICH air-fuel mixture.
- 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 with a LEAN air-fuel mixture.
- Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.
CHECK FOR INTERMITTENT PROBLEMS
HINT:
Hand-held tester only:
Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the ECM is in check mode with hand-held tester. In check mode, the ECM uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default), which uses 2 trip detection logic.
a. Clear the DTCs.
b. Set the check mode.
c. Perform a simulation test.
d. Check the connector and terminal.
e. Wiggle the harness and the connector.