We report new ab initio calculations of the three-dimensional potential energy surfaces for the Renner-effect coupled [image omitted] ground electronic state and [image omitted] first excited electronic state of the CH [image omitted] molecule. We also make an ab initio calculation of the spin-orbit coupling surface [image omitted] between these states. Using these ab initio surfaces in our computer program RENNER, we calculate term values and absorption line intensities, and compare with recently observed high resolution spectra. Adjusting two parameters in the potential surfaces we are able to achieve satisfactory agreement with the experimental results except for those that involve the [image omitted] state ( [image omitted], l = 1) vibronic level. The implication of this disagreement is discussed.