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.
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 Drive Cycles |
