You should specify additional preprocessing arguments with train control
A list of options to pass to preProcess. The type of pre-processing is passed in the pre proc option by train.
I will use the Sonar dataset from the mlbench.
ctrl <- trainControl(preProcOptions = list(thresh = 0.95))
mod <- train(Class ~ .,
data = Sonar,
method = "pls",
trControl = ctrl)
You should make sure to go through it.
Hope this answer helps you!