| Case 1 |
Main Action |
- Response rate check after leaving fuel cut-off (Rich-to-Lean)
|
- Leak in intake or exhaust system
- Faulty fuel system
- Front and rear HO2S connections reversed.
- Poor connection or damaged harness
- HO2S contamination
|
| Prerequisite Condition |
- O2 Sensor operative readiness is detected
- O2 sensor internal resistance is lower than or equal to 3000Ω
- Catalyst temperature model is higher than 400°C (752°F)
- Downstream O2 sensor signal voltage is greater than 0.6V at entry into fuel cut-off
- Battery voltage is between 11V and 16V
|
| Threshold value |
- Signal gradient from 0.6V to 0.3V at entry in fuel cut off is under 1000 mV/s
|
| Diagnosis Time |
- 3 valid fuel cut-off phases
|
| Case 2 |
Main Action |
- Response rate check after leaving fuel cut-off (Lean-to-Rich)
|
| Prerequisite Condition |
- O2 Sensor operative readiness is detected
- Mass air flow integral, after leaving fuel cut-off, is greater than 100g
- Catalyst temperature model is higher than 400°C (752°F)
- Exhaust gas temperature model, at sensor location, is greater than 400°C (752°F)
- Battery voltage is between 11V and 16V
- O2 sensor internal resistance is lower than or equal to 3000Ω
|
| Threshold value |
- Signal gradient from 0.3V to 0.6V at entry in fuel cut off is under 1500 mV/s
|
| Diagnostic Time |
- 3 valid diagnostic cycles
|
| MIL On Condition |
|