| Case 1 |
Main Action |
- Response rate check at entry into fuel cut-off (Rich-to-Lean)
|
- Poor connection or damaged harness
- Leakage in intake or exhaust system
- Faulty fuel system
- Front and rear HO2S connections reversed
- HO2S contamination
|
| Prerequisite condition |
- Downstream O2 Sensor operative readiness is detected.
- O2 sensor internal resistance is lower than or equal to 3KΩ.
- Catalyst temperature model is higher than 487°C (908.6°F).
- Downstream O2 sensor signal is greater than 0.6V at entry into fuel cut-off.
- Battery voltage is between 11V and 16V.
- Mass air flow threshold for diagnosis of the switching gradients is between 10kg/h and 50 kg/h.
|
| Threshold Value |
- Average signal gradient from 0.6V to 0.3V at entry into fuel cut off is lower than 1500 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 |
- Downstream O2 Sensor operative readiness is detected.
- Mass air flow integral, after leaving fuel cut-off, is greater than 100g.
- Mass air flow integral is between 10g and 250g.
- Catalyst temperature model is greater than 487°C (908.6°F).
- Exhaust gas temperature model at sensor location is higher than 400°C (752°F).
- Battery voltage is between 11V and 16V.
- O2 sensor internal resistance is lower than or equal to 3KΩ.
|
| Threshold Value |
- Average signal gradient from 0.3V to 0.6V after leaving fuel cut off is lower than 1500 mV/s.
|
| Diagnosis Time |
- 3 valid diagnostic cycles
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| MIL On Condition |
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