1. Oxygen Sensor (B1/S1)
The normal operating temperature of the HO2S(Heated Oxygen Sensor) ranges from 350 to 850℃(662 to 1562℉). The HO2S heater greatly decreases the amount of time required for fuel control to become active. The PCM provides a pulse width modulated control circuit to adjust current through the heater. When the HO2S is cold, the value of the resistance is low and the current in the circuit is high. On the contrary, if the temperature in the resistor of the sensor rises, the current drops gradually.
The normal operating temperature of the HO2S(Heated Oxygen Sensor) ranges from 350 to 850℃(662 to 1562℉). The HO2S heater greatly decreases the amount of time required for fuel control to become active. The PCM provides a pulse width modulated control circuit to adjust current through the heater. When the HO2S is cold, the value of the resistance is low and the current in the circuit is high. On the contrary, if the temperature in the resistor of the sensor rises, the current drops gradually.
The PCM monitors the HO2S(B1/S1) transition frequency for predetermined time. During the monitoring period, the PCM calculates transition times that the front HO2S switches from rich to lean and from lean to rich. With this information, an average frequency for all switches can be determined. The PCM sets DTC P0133 when the average frequency is too slow.
The PCM monitors front oxygen sensor amplitude level and compares it to predetermined minimum amplitude value which could increase emission or disturb lambda control by the effect of aging on the oxygen sensor. The PCM sets DTC P0133 when the amplitude of oxygen sensor is equal to or less than minimum amplitude threshold.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Check Lambda control regulation frequency | 1. Leak in intake or exhaust system 2. Poor connection or damaged harness 3. HO2S contamination |
Enable Conditions |
•
Coolant temperature >73℃(163℉)
•
550℃(1022℉)< Catalyst temperature model <850℃(1562℉)
•
Vehicle speed >3mph
•
1300< Engine speed(rpm) <3200rpm
•
0.3g/rev.< MAF <0.8g/rev.
•
Canister load <0.5
•
Lambda control active
•
Stable driving condition
•
No opening/closing of canister purge valve
•
70kPa(700hPa)< Ambient pressure
•
No relevant failure
•
11V< Battery voltage <16V | |
Threshold Value |
•
Average Ratio between measured and maximum allowed frequency >1 | |
Diagnostic Time |
•
50 lambda controller cycles | |
Mil On Condition |
•
2 Driving Cycles |
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Check HO2S Signal Amplitude | 1. Leak in intake or exhaust system. 2. Poor connection or damaged harness 3. HO2S contamination |
Enable Conditions |
•
see catalyst diagnosis(P0420) activation condition
•
No relevant failure
•
11V<Battery voltage<16V | |
Threshold Value |
•
Integral ( Lambda signal amplitude measured / Lambda signal amplitude of a slow sensor ) > 1.0 | |
Diagnostic Time |
•
25 lambda controller cycle | |
Mil On Condition |
•
2 Driving Cycles |
BINARY
LINEAR
