In A Chopin was probably driven by the echo of the bass note; however, in the further course of the Scherzo, already from b. 39-40, he started taking into consideration harmonic changes in similar situations, each time inserting a 
before a bar based on a local dominant seventh chord. A respective correction in b. 171-173 (moving the mark from b. 173 to the end of b. 171) proves that it was an informed decision. In turn, the unfinished pedalling in b. 40 and missing indications in further, analog. b. 148, 172, 599 and 623 suggest that Chopin, while writing pedalling in A, considered marking it in those bars to be superfluous. However, while proofreading FC the composer added the pedalling copied from A*, so that in each of those places it encompasses an entire four-bar section, whereas the last bar with a changed chord is provided with a separate pedal. In the main text we take into account those undoubtedly authentic and most precise markings, which in the discussed place covers the pedal change added under the bars in FC (→GE).
* A complete chronology of Chopin's writing pedalling marks in A and FC gives rise to doubts. In some places, e.g. in b. 145-175, it seems that the entire pedalling in FC was written by Chopin, including the marks featured in A. It means that they were most likely absent in A at the time when Fontana was copying it; therefore, they could have been added later than the entries in FC. However, it is uncertain, since one cannot exclude an accidental omission of pedalling marks by the copyist on an entire page of the manuscript, including those bars (in spite of the fact that the marks were already in A), which would have meant that Chopin then had to add them. Moreover, even if the indications of A were added after FC had been drawn up, it does not imply that they are to be added after the corrections introduced in FC: since Chopin had both manuscripts at his disposal, he could have corrected them in any order or in parallel.
Compare the passage in the sources »
category imprint: Differences between sources; Corrections & alterations
issues: Authentic corrections of FC
notation: Pedalling