3.
Monitor "HO2S(B1S2)" parameter on scantool.
HO2S(B1/S2) is in the rear side of Catalytic Converter to check the proper operation of catalyst. Oxygen density after the catalytic converter has to be within specific range (around 0.5V when there is no acceclation and deceleration.)If the oxygen density changes in accordance with HO2S(B1/S1), it means the poor performance of catalytic converter.
If the internal resistance of heater is over the threshold value under enable conditins, PCM sets DTC P0141.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Check heating condition | ● Poor connection ● Open or short to ground in signal circuit ● B1S2 ● ECM |
Enable Conditions | ● Catalyst temperature (model) 200∼550℃ ● Intake air temperature 〉 -7℃ ● Battery voltage 10.7∼16.1V | |
Threshold Value | ● Internal resistance 〉 threshold f (cat. temp., heater power) | |
Diagnostic Time | ● Above 6 sec | |
MIL | ● ON |
※ B1S2 : upstream oxygen sensor / B1S2 : downstream oxygen sensor
ITEM | Specification |
Heater Resistance | Approx. 9.0 (20℃) |
Connect scantool to DLC (Data Link Cable).
Warm up the engine to normal operating temperature.
Monitor "HO2S(B1S2)" parameter on scantool.
Is the "HO2S(B1S2)" parameter displayed correctly?
▶Fault is intermittent caused by poor contact in the sensor’s and/or ECM’s connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poorconnection, ending, corrosion, contamination, deterioration, or damage. Repair or replace asnecessary and go to "Verification of Vehicle Repair" procedure.
▶ Go to "Terminal and Connector Inspection" procedure.
Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and go to "Verification of vehicle Repair" procedure.
▶ Go to " Power Circuit Inspection " procedure.
IG "OFF".
Disconnect HO2S(B1S2) connector.
IG "ON" ＆ ENG "OFF".
Measure voltage between terminal 3 of HO2S (B1S2) harness connector and chassis ground.
Specification : B+
Is the measured voltage within specification?
▶ Go to "Control Circuit Inspection" procedure.
▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
IG "OFF".
Disconnect HO2S(B1S2) connector.
IG "ON" ＆ ENG "OFF"
Measure voltage between terminal 4 of HO2S(B1S2) harness connector and chassis ground.
Specification : Approx. 3.5V
Is the measured voltage within specification?
▶ Go to "Component Inspection" procedure.
▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
Check Heater resistance.
IG "OFF".
Disconnect HO2S(B1S2) connector.
Measure resistance bwteen terminal 3 and 4 of HO2S(B1S2) connector.(Component Side)
ITEM | Specification |
Heater Resistance | Approx. 9.0 (20℃) |
Is the measured resistance within specification?
▶ Substitute with a known - good ECM and check for proper operation.
▶ If the problem is corrected, replace ECM and go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known - good HO2S and check for proper operation.
▶ If the problem is corrected, replace HO2S 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.
Clear the DTCs and Operate the vehicle within DTC Enable conditions in General information.
Are any DTCs present ?
▶ Go to the applicable troubleshooting procedure.
▶ System is performing to specification at this time.
