1.14.8.1 General description
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The purpose of the diagnosis is to detect faults of the knock sensor. Therefore the signal range and dynamics of a low pass filtered knock signal is checked.
If the signal range exceeds an upper or lower threshold a failure is detected.
An implausible knock signal is detected by using a statistical analysis. The difference between filtered knock signal and raw knock signal is estimated for a certain number of combustion cycles.
All error symptoms are de-bounced.
Error Symptoms
- Noise level above valid range
- Noise level below valid range
- Knock sensor signal not plausible