10.1 Calibration resistor check
The resistance of the calibration resistor mounted on the powertrain control module is constant. If the difference between its nominal and measured values exceeds a calibration, a HSVsig fault will be set. A proper galvanic cell temperature determination will be impossible if the HSVsig fault is present.
37.2.1.1 Test Pass-by sufficient dynamic adjustment
If the signed difference between a new commanded valve timing and the current valve timing exceeds a calibrated deviation a 'monitoring' cycle with two calibrated timers is started.
The first time interval is used to check whether the VVT system was able to achieve the commanded adjustment by analyzing the measured values of the camshaft position sensor. If the absolute deviation value was achieved and the second timer has elapsed the monitoring cycle represents a successful adjustment. For a complete 'test pass' (incrementation of 'test pass' counter), an identical behavior in both adjustment directions (advancing and retarding) is necessary.
During the 'monitoring' cycle the commanded valve timing must stay above or below the absolute deviation value depending on the adjustment direction at the beginning, otherwise the 'monitoring' cycle will be aborted.
If this 'test pass' was successfully performed in both adjustment directions the 'stuck cam' and 'slow response' counters are decremented by two (if not zero).
Scheme 156
37.2.1.2 Test Pass-with insufficient dynamic adjustment
If the signed difference between commanded valve timing and current valve timing does not exceed a calibrated deviation (insufficient dynamic adjustment) the following 'test pass' is performed.
Every time when the commanded camshaft position exceeds the trigger deviation range and stays above the absolute deviation value for at least the time of the second time interval the 'test pass' counter is incremented. This means that this monitor is almost equal to the other checks (where the dynamic adjustment is sufficient) with the only difference that a calibrated reference point is used (Scheme 157)
This monitor is interrupted if
Scheme 157
- the commanded valve timing 'monitoring' cycle has been triggered due to a sufficient dynamic adjustment (till end of cycle) or
- a 'slow response' error has been found (is present) without exceeding the 'slow response' threshold counter (still in debouncing mode) or
- a 'stuck cam' has been found (is present) without exceeding the 'stuck cam' threshold counter (still in debouncing mode) and the current valve timing is close to (calibrated range) the stored 'stuck cam' VVT position.