The HO2S(Heated Oxygen Sensor) is used to supply the PCM with information regarding the composition of the air/fuel mixture. The HO2S is positioned in the exhaust pipe ahead of the TWC. To measure the oxygen content, the HO2S requires a supply of ambient air as a reference. Since this is supplied through the wiring, the lead must not be clamped or damaged in any other way. The HO2S produces a voltage that varies between 0.1V and 0.9V under normal operating conditions. The Engine Control Module (PCM) monitors this voltage and determines if the exhaust gas is lean or rich. If the voltage input at the PCM is under approx. 0.45V the exhaust is lean, and if the voltage input is over approx. 0.45V the exhaust is rich. The PCM constantly monitors the HO2S signal during closed loop operation and compensates for a rich or lean condition by decreasing or increasing injector pulse width as necessary.
PCM sets DTC P0130 if the PCM detects that the front HO2S signal circuit is open.
Item
Detecting Condition
Possible Cause
DTC
Strategy
Case 1
Voltage range check
Open in signal harness
Open in ground harness
Poor connection or damaged harness
Faulty Heated O2 Sensor(HO2S)
Case 2
Check time for O2 sensor readiness detection(to start feedback control)
Enable
Conditions
10V< Battery voltage <16V
O2 sensor pre-heating phase finished
Exhaust gas temperature > 650?(1202?)
Lambda close loop control activated
Minimum time after start versus coolant temperature at start(-40? : 90sec./-20? : 60sec./0? : 53sec./15? : 32sec./55? : 32sec.)
Threshol
Value
0.38V< HO2S < 0.47V
O2 sensor operative ready
Diagnostic Time
10 sec.
32~90 sec (depending on start coolant temp.)
MIL On Condition
2 Driving Cycles
? Sector A : Before Oxygen Sensor(B1S1) activated.
? Sector B : Normal signal of Oxygen Sensor(B1S1) during idle.
? Sector C : Line break in signal circuit.