3.
Monitor the "B1S2" parameters on the 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 counter that the signal voltage changes rapidly is over 5 times, PCM sets DTC P2232.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Rationality check | ● Poor connection ● Short to power in signal circuit ● B1S2 ● ECM |
Enable Conditions | ● After enough heated ● Battery voltage 〉 10.7V ● Catalyst temperature (model) 〈 800℃ ● Time after dew point end detected 〉 10 sec | |
Threshold Value | ● Counter of [ △ushk ＞ 2V after heater on→off ] ＞ 5 times | |
Diagnostic Time | ||
MIL | ● ON |
△ushk : Sum of the signal voltage change value (B1S2)
※ B1S1 : upstream oxygen sensor / B1S2 : downstream oxygen sensor
Connect scantool to Data Link Connector(DLC).
Warm up the engine to normal operating temperature.
Monitor the "B1S2" parameters on the scantool.
Are the parameters displayed correctly?
▶ 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, poorconnection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary 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 "B1S2 circuit inspection" procedure.
IG "OFF".
Disconnect HO2S(B1/S2) connector.
IG "ON" ＆ ENG "OFF".
Measure voltage between terminal 1 of HO2S(B1/S2) and chassis ground.
Specification : Approx. 0.45V
Is the measured voltage within specification?
▶ Go to "Component Inspection" procedure.
▶ Repair short to power in signal circuit and then, go to "Verification of Vehicle Repair"procedure.
Visual Inspection.
IG "OFF"
Disconnect HO2S(B1/S2) connector.
Check that HO2S(B1S2) is contaminated or damaged by foreign materials.
Has a problem been found?
▶ Go to "Check ECM" as follows.
▶ Substitute with a known - good HO2S(B1/S2) and check for proper operation.
▶ If the problem is corrected, replace HO2S(B1/S2) and go to "Verification of Vehicle Repair" procedure.
Check ECM.
IG "OFF".
Connect scantool and Engine "ON".
Select simulation function on scantool.
Simulate voltage at terminal 1 of HO2S(B1/S2) signal connector.
Does the signal value of HO2S(B1/S2) change according to simulation voltage?
▶ Thoroughly check connectors for looseness, poor connection, bending, corrosion,contamination, deterioration, or damage. Repair or replace as necessary and go to "Verificationof Vehicle Repair" procedure.
▶ 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.
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.
