  CDMSlite Run 2 was a search for weakly interacting massive particles (WIMPs)
with a cryogenic 600 g Ge detector operated in a high-voltage mode to optimize
sensitivity to WIMPs of relatively low mass from 2 - 20 GeV/$c^2$. In this
article, we present an effective field theory (EFT) analysis of the CDMSlite
Run 2 data using an extended energy range and a comprehensive treatment of the
expected background. A binned likelihood Bayesian analysis was performed on the
recoil energy data, taking into account the parameters of the EFT interactions
and optimizing the data selection with respect to the dominant background
components. Energy regions within 5$\sigma$ of known activation peaks were
removed from the analysis. The Bayesian evidences resulting from the different
operator hypotheses show that the CDMSlite Run 2 data are consistent with the
background-only models and do not allow for a signal interpretation assuming
any additional EFT interaction. Consequently, upper limits on the WIMP mass and
coupling-coefficient amplitudes and phases are presented for each EFT operator.
These limits improve previous CDMSlite Run 2 bounds for WIMP masses above 5
GeV/$c^2$.
