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.
In case the sensor output is 0.4~0.52 V during 600sec or the internal resistance is over 40 ㏀ under enable conditions, ECM sets DTC P0136. ( This DTC might be caused by the malfunction of Heater circuit, so, check the heater circuit first. )
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Signal check, wiring interruption | ● Poor connection ● Open or short in signal circuit ● B1S2 ● ECM |
General Enable Conditions | ● After enough heated ● Battery voltage > 10.7V ● Catalyst temperature (model) < 800℃ | |
Case1 | Threshold Value | ● Sensor voltage : 0.4~0.52 V |
Diagnostic Time | ● 600 sec | |
Case2 | Enable Conditions | ● Catalyst temperature (model) > 450 ℃ |
Threshold Value | ● Internal resistance > 40 ㏀ | |
MIL | ● ON |
※ B1S2 : upstream oxygen sensor / B1S2 : downstream oxygen sensor
ITEM | Specification |
Heater Resistance(Ω) | Approx. 9.0Ω(20℃) |
