188.8.131.52. System of neutralization
System effectiveness of neutralization is lower than the threshold level (P0420)
The PCM block compares the number of inversions of forward and back sensors of concentration of oxygen to heating during certain time. The PCM block controls the number of inversions of the back sensor at the set number of inversions of the forward sensor when the following conditions are satisfied. The PCM block finds a ratio of inversions:
– frequency of rotation of the engine – 1410–3000 min.-1 (models with the mechanical transmission);
– frequency of rotation of the engine – 1281–3000 min.-1 (models with the automatic transmission);
– settlement loading of 15-50% *.
If the ratio of inversions – below threshold level, the PCM block decides that work of system of neutralization worsened.
* The maximum calculated value of loading changes depending on the frequency of rotation of the engine