P2A01
DTC P2A01 HO2S CIRCUIT RANGE / PERFORMANCE (BANK 1 / SENSOR 2)Component Location:
GENERAL DESCRIPTION
In order to control emissions of the CO, HC and NOx components of the exhaust gas, heated oxygen sensor (HO2S), mounted on the front side and rear side of catalytic converter, detects the oxygen content in the exhaust gas. The front HO2S signal is used to control air/fuel ratio (closed loop fuel control) and the rear HO2S signal is used to monitor front HO2S and catalyst for proper operation. The HO2S requires a minimum temperature to operate properly and provide a closed loop fuel control system. The HO2S contains the heater element to reduce its warming-up time and ensure its performance during all driving conditions. The oxygen sensor generates a voltage that indicates the difference between the oxygen content of the exhaust stream and the oxygen content of ambient air. When the exhaust stream is " rich," there is more oxygen in the ambient air than in the exhaust stream, so the voltage will be higher.
DTC DESCRIPTION
Checking output signals from HO2S during deceleration fuel cut-off, if the HO2S's response time is too long, PCM sets P2A01. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycles.
DTC Detecting Condition:
Specification:
Signal Waveform And Data:
SIGNAL WAVEFORM AND DATA
After warming-up, if accelerator pedal is released suddenly around 4000 rpm, the HO2S signal reading will be lower than 200 mV resulting from Fuel cut-off for the moment. Conversely, if suddenly accelerator pedal is depressed, HO2S signal reading will be around 0.6 V -1.0 V. At idle, HO2S signal will switch from lean to rich normally.
MONITOR DTC STATUS
1. Check DTC Status
1. Connect scantool to Data Link Connector(DLC).
2. IG "ON".
3. Select "DTC" button, and then Press "DTC Status" to check DTC's information from the DTCs menu.
4. Read "DTC Status" parameter
5. Is parameter displayed "Present fault?
YES - Go to "Component Inspection" procedure.
NO - Clear DTC and check if this DTC is set after test-driving under enable conditions. If DTC isn't displayed after the test, it was intermittent fault. Go to "Verification of Vehicle Repair"procedure.
COMPONENT INSPECTION
1. Replace the HO2S.
2. Clear DTC with scantool.
3. Start the engine and warm it up until the radiator fan comes on( more than at least 10 minutes).
4. Drive at a steady speed between 45-55 mph(72-88 km/h) and then release the accelerator(tip-out).
5. Repeat Step 4 to 5 more than 5 times.
6. Does the scan tool show DTC?
YES - Substitute with a known - good PCM and check for proper operation. If the problem is corrected, go to "Verification of Vehicle Repair" procedure.
NO - Troubleshooting is finished.
NOTE: There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM. Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "DTC" button.
2. Press "DTC Status" button and confirm that "DTC Readiness Flag" indicates "Completed". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
3. Read "DTC Status" parameter
4. Is parameter displayed "History(Not Present) fault"?
YES - System performing to specification at this time. Clear the DTC
NO - Go to the applicable troubleshooting procedure.