5.
Read "DTC Status" parameter.
The catalyst’s efficiency is demonstrated by its ability to oxidize CO and hydrocarbon emissions. The Powertrain Control Module (PCM) compares the output signals of the front and rear oxygen sensors to determine whether the output of the rear sensor is beginning to match the output of the front oxygen sensor. Air/fuel mixture compensation keeps the frequency of the front oxygen sensor high due to the changes from rich-to-lean combusition. The catalyst causes the rear oxygen sensor to have a lower frequency. As the catalyst wears, the rear oxygen sensor’s signal trace begins to match the front oxygen sensor’s signal trace. That is because the catalyst becomes saturated with oxygen and cannot use the oxygen to convert hydrocarbon and CO into H₂O and CO₂ with the same efficiency as when it was new. A completely worn catalyst shows a 100% match between the frequency of the front and rear sensors.
If the B1S1 signal is advanced compared to the B1S2 controller value, P2096 is stored.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● O2 sensor characteristic line shift | ● Catalyst converter ● HO2S (B1/S1) |
Enable Conditions | ● Dew point end detected ● Required lambda = 1 ● Battery voltage ＞ 10.7V ● Exhaust gas temperature (model) : 600℃ ~ 800℃ ● Heater control enabled ● 1000rpm ＜ Engine speed ＜ 3800rpm ● Engine load : 15 ~ 78.8 % ● No error on the B1S2. ● B1S2 is activated | |
Threshold Value | ● The second controller by B1S2 〉0.8sec | |
Diagnostic Time | ● 15 sec | |
MIL ON Condition | ● 2 driving cycle |
※ B1S1 : upstream oxygen sensor / B1S2 : downstream oxygen sensor
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 clog on Exhaust gas system
Key "OFF".
Check clog on muffler or catalyst converter.
Is Exhaust gas system O.K?
▶ Go to "Intake air system check" procedure.
▶ Repair as necessary and go to "Verification of vehicle Repair" procedure.
Intake air system check.
Check leakage on Intake air system
▶ Check looseness, deterioration or contamination on throttle body and gasket.
▶ Check contamination, damage or crack on intake manifold, ISCA and injectors.
▶ Check for contamination or sticking on the ISCA assembly.
Is there any leakage?
▶ Repair as necessary and go to "Verification of vehicle Repair" procedure
▶ Go to "Fuel line check" procedure.
Fuel line check.
Check "Fuel line system"
▶ Check looseness of connectors on fuel line.
▶ Check looseness, damage, or interference of vacuum hose on fuel line.
▶ Check damage, leakage or bending on fuel line pipe.
Is fuel line normal?
▶ Go to "Fuel line pressure check" procedure.
▶ Repair as necessary and go to "Verification of vehicle Repair" procedure.
Fuel line pressure check.
Key "OFF".
Disconnect a fuel pump relay.
Engine start and wait until engine stop. and then key "OFF".
Connect a fuel pump relay.
Connect fuel pressure guage using the correct adapter.
Start the engine and record fuel pressure.
Specification : Approx. 3.5 kg/cm²
Is the fuel pressure normal?
▶ Go to "Component inspection" procedure.
▶ Check clogging on the fuel filter.
▶ Check the supply pressure of fuel pump.
▶ Repair as necessary and go to "Verification of vehicle Repair" procedure
PCV(Positive Crankcase Ventilation) valve check.
Key "OFF".
Disconnect PCV valve.
Check the movement of plunger by putting in and out a thin stick.
Is the movement of plunger normal?
▶ Go to "injectors check" procedure.
▶ Substitute with a known - good PCV valve and check for proper operation.
▶ If the problem is corrected, replace PCV valve and go to "Verification of Vehicle Repair" procedure.
Injector check
Key "OFF".
Disconnect injectors.
Check clog on injectors.
Measure the resistance between terminal 1 and 2 of injectors(Component side).
Temperature [℃ (℉)] | Resistance (Ω) |
20 (68) | 13.8 ~ 15.2 |
Is the measured resistance within specifications ?
▶ Go to "Sensors related to air/fuel ratio check" procedure.
▶ Substitute with a known - good Injector and check for proper operation.
▶ If the problem is corrected, replace Injector and go to "Verification of Vehicle Repair" procedure.
Sensors related to air/fuel ratio check.
Check the output data of sensors related to air/fuel ratio (HO2S, MAPS, TPS, ECTS, PCSV, Injectors, etc) on scantool. (Refer to each DTC guide procedure.)
Are those sensors normal?
▶ 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.
Repair or replace as necessary. And then, 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.
