Imu data not using pitch or roll

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I am working on getting my Turtlebot 2 to detect a change in slope. I was hoping to use the built in gyroscope in kobuki to detect when the pitch changes more than some arbitrary number. The problem is, that the Imu data is only showing 0's for both x, and y. Is there any way to "activate" the gyro to use all three orientations? The covariance for these values are also 0. It looks like this

header:
  seq: 213
  stamp:
    secs: 14...
    nsecs: 85...
  frame_id: gyro_link
orientation:
  x: 0.0
  y: 0.0
  z: 0.02248192
  w: .99925125
orientation_covariance: [1.79769206832e+308, 0.0, 0.0, 0.0, 1.79769206832e+308, 0.0, 0.0, 0.0, 0.05]
angular_velocity:
  x: 0.0
  y: 0.0
  z: -.01188310581
angular_velocity_covariance: [same as orientation_covariance]
linear_acceleration:
  x: 0.0
  y: 0.0
  z: 0.0
linear_acceleration_covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]