5.
Read "DTC Status" parameter.
The heated oxygen sensors are mounted on the front side and the rear sied of Catalytic Converter (warm-up catalytic converter), which detects the oxygen concentration 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 heated oxygen snesor (HO2S) produces a voltage that varies between 0V and 1V. When the air/fuel ratio is lean, the oxygen concentration in the exhaust gas increases and the front HO2S outputs a low voltage (approximately 0 ~ 0.1 V).When the air/fuel ratio is rich, the oxygen concentration in the exhaust gas decreases and the front HO2S output a high voltage (approximately 0.8 ~ 1 V). The ECM constantly monitors the HO2S and increases or decreases the fuel injection duration by using the HO2S signal, which is called closed-loop fuel control operation.
If there is abnormal response rate of HO2S under enable conditions, ECM sets DTC P0133.
( This DTC might be caused by the malfunction of Heater circuit, so, check the heater circuit first. )
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Response rate | ● Poor connection ● leak or clog in intake air system ● Injector ● Fuel pressure ● HO2S (B1S1) |
Enable Conditions | ● Dew point end detected ● Required lambda = 1 ● Battery voltage ＞ 10.7V ● Exhaust gas temperature (model) : 600℃ ~ 800℃ ● Heater control enabled ● Engine speed 1800∼2800rpm ● Engine load 20∼65% ● Exhaust gas temperature (model) ＞ 450℃ | |
Threshold Value | ● Cycle period of B1S1 signal ＞ 2.85 sec | |
Diagnostic Time | ● 20 cycle | |
MIL ON Condition | ● 2 driving cycle |
※ B1S1 : upstream oxygen sensor / B1S2 : downstream oxygen sensor
Specification | 0.1 ~ 0.9V |
Connect scantool to Data Link Connector(DLC).
IG "ON".
Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC'sinformation from the DTCs menu
Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditionsnoted in the freeze frame data or enable conditions noted in the DTC detecting condition.
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
History fault : DTC occurred but has been cleared.
Present fault : DTC is occurring at present time.
▶ Fault is intermittent caused by poor contact in the sensor’s and/or ECM’s connector or wasrepaired and ECM memory was not cleared. Thoroughly check connectors for looseness,poor connection, bending, corrosion, contamination, deterioration, or damage.Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
▶ Go to "Terminal & Connector Inspection" procedure
Check leakage or clog of air.
Check contamination, clog and installation of gasket
▶ Any damage or installation of throttle body gasket.
▶ Any damage or installation of gasket between intake manifold and surge tank.
▶ Clog or contamination of intake manifold and injector by foreign materials
▶ Contamination and open stuck between surge tank and PCSV by foreign materials
▶ Any damage or contamination of HO2S(B1/S1) by foreign materials.
Has a problem been found?
▶ Go to " Check Fuel Line" as follows.
▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
Check Fuel Line.
Check Clog, contamination and installation of Fuel Line as follows.
▶ Connection for each connectors in Fuel Line.
▶ Damage, interference and installation of vaccum hose connected to Fuel Line.
▶ Bend, Leakage and squeeze of pipe in Fuel Line.
Has a problem been found?
▶ Go to "Check Fuel Pressure" as follows.
▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
Check Fuel Pressure.
IG "OFF".
Disconnect fuel pump relay from junction box in passenger compartment.
Start engine and await until engine is off and then, IG "OFF".
Connect fuel pump relay again.
Connect fuel pressure gauge on the fuel filter with fuel pressure gauge adaptor.
Start engine again and measure fuel pressure.
Specification : Approx. 3.5㎏/cm²
Is the fuel pressue normal?
▶ Go to "Component Inspection" procedure.
▶ Check any damage of fuel return hose or pipe.
▶ Check any stuck of the valve in the fuel pressure regulator.
▶ Repair or replace as necessary and then, go to 'Verification of Vehicle Repair" procedure.
Visual Inspection.
IG "OFF"
Disconnect HO2S(B1/S1) connector.
Check that HO2S(B1S1) is contaminated or damaged by foreign materials.
Has a problem been found?
▶ Go to "Check HO2S(B1/S1) performance" as follows.
▶ Substitute with a known - good HO2S(B1/S1) and check for proper operation.
▶ If the problem is corrected, replace HO2S(B1/S1) and go to "Verification of Vehicle Repair" procedure.
Check HO2S(B1/S1) performance.
IG "OFF".
Connect probe to terminal 1 of HO2S(B1/S1) connector and select oscilloscope function with scantool.
Warm up the engine to normal operating temperature.
Measure signal waveform of HO2S(B1/S1) with scantool.
Is the measured signal waveform within specification?
▶ Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage. So, check poor connections and the related circuit between ECM and component thoroughly. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known - good HO2S(B1/S1) and check for proper operation.
▶ If the problem is corrected, replace HO2S(B1/S1) and go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete".
If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
▶ System performing to specification at this time. Clear the DTC.
▶ Go to the applicable troubleshooting procedure.
