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C & K Series

  1. Remove instrument cluster from vehicle. Refer to INSTRUMENT CLUSTER . Plug DRAC calibration connector from Service Kit (25085515) into back of instrument cluster and momentarily touch DRAC calibration connector wires to vehicle battery terminals. See Fig 1 and Fig 2.
    Fig 1: C & K Series Speedometer Calibration Components
    G117161Courtesy of GENERAL MOTORS CORP.
    NOTE: The calibration connector from service kit (25085515) should be used a maximum of 10 times. It is not necessary to perform step  1 if speedometer has been previously recalibrated. Follow instructions provided with service kit.
  2. Use vehicle axle ratio, corresponding tire size and tread type from SPEEDOMETER CALIBRATION SPECIFICATIONS  at end of this article to find appropriate pins to be removed from calibration clip. Rectangular end of calibration clip is at the top. Pins are numbered 1 through 8 from top to bottom. See Fig 1.
  3. Remove pins by bending them back and forth with long needle nose pliers. Insert modified calibration clip into 8 holes in rectangular slot on back of instrument cluster. Install instrument cluster in vehicle. See Fig 2.
Fig 2: C & K Series Speedometer Calibration Svc Kit Comp & Loc
G90E14930Courtesy of GENERAL MOTORS CORP.