2000 Nissan Xterra Owner's Manual - Page 253

If step one through seven interrupted, repeat the preceding step. Any safe driving mode is acceptable between steps. Do not stop the engine until step seven is completed. If you cannot or do not want to perform the driving pattern, an authorized NISSAN dealer can conduct it for you. Serious damage will occur to the 4WD system if the transfer control lever is not in the 2H position. Dynamometer testing for Inspection/Maintenance (I/M) test (US only) Due to legal requirements in some states/areas, your vehicle may be tested for emissions on a dynamometer. The transfer control lever (if so equipped) MUST be in the 2H position for I/M testing on a two wheel dynamometer. WARNING If the transfer control lever is not in the 2H position during the dynamomter I/M testing, the vehicle could come off the dynamometer and cause serious personal injury and/or body damage to the vehicle. 10-28 Technical and consumer information