How does BVP5C algorithm linearize nonlinear algebraic equations?

My understanding is that BVP5C forms set of generally nonlinear algebraic equation in each collocation interval, linearizes them, and iteratively solves with linear equation solvers of MATLAB. How is Linearization done? I could not find the answer in the following papers:

1. Shampine LF, Kierzenka J, Reichelt MW. Solving Boundary Value Problems for Ordinary Differential Equations in Matlab with bvp4c. :27.

2. Kierzenka J, Shampine LF. A BVP Solver that Controls Residual and Error. 2008;16.