 
| Subject: | Guidelines for Proper Use of Labor Operation Numbers When Servicing Transfer Case | 
| Models: | 2006 and Prior Passenger Cars and Light/Medium Duty Trucks | 
|  | with Four-Wheel Drive (4WD) or All-Wheel Drive (AWD) System | 
When servicing the transfer case, some dealers are using the incorrect labor operation number when submitting warranty claims. The following information is a guideline to further assist dealers in the proper use of transfer case related labor operation
numbers. This information provides the correct labor operation number/description, vehicle application and vehicle exceptions.
| Labor Operation | Description | 
| K4120 | Switch, Vacuum Control - Replace | 
| • | This labor operation applies to NVG 233 and NVG 236 (RPO NP1 and NP8) transfer cases. | 
| • | The following transfer cases DO NOT incorporate a vacuum switch. Labor operation K4120 will NOT apply to these transfer cases. | 
| - | NVG 226/236/246 (RPO NP8) | 
| - | BW 4482/4484/4493 (RPO NR4) | 
| Labor Operation | Description | 
| K4121 | Module, Transfer Case - Reprogram | 
The following transfer cases DO NOT incorporate reprogrammable modules. Labor operation K4121 will NOT apply to these transfer cases.
| • | Isuzu T150/NVG 233 (RPO NP1) | 
| • | NVG 246 (RPO NP8) (1998-2002) | 
| Labor Operation | Description | 
| K4122 | Module, Transfer Case Shift - Replace | 
The following transfer cases DO NOT incorporate shift control modules. Labor operation K4122 will NOT apply to these transfer cases.
| Labor Operation | Description | 
| K4123 | Switch, Transfer Case Select - Replace | 
The following transfer cases DO NOT incorporate shift select switches. Labor operation K4123 will NOT apply to these transfer cases.
| Labor Operation | Description | 
| K4124 | Sensor Assembly, Transfer Case Range Selector - Replace | 
The following transfer cases DO NOT have replaceable actuator position sensors. Labor operation K4124 will NOT apply to these transfer cases.
| • | NVG 246 (RPO NP8) (1998-2002) | 
| • | BW 4482/4484/4493 (RPO NR4) | 
| Labor Operation | Description | 
| K4126 | Actuator Assembly, Transfer Case - Replace | 
The following transfer cases are NOT equipped with actuator assemblies. Labor operation K4126 will NOT apply to these transfer cases.
RPO Definitions
| RPO | Description | 
| NP1 | Transfer Case - Electronic Shift Control, Two-Speed | 
| NP2 | Transfer Case - Manual Shift Control, Two-Speed | 
| NP3 | Transfer Case - All Wheel Drive (AWD) | 
| NP4 | Transfer Case - Active, All Wheel Drive (AWD) | 
| NP8 | Transfer Case - Active, Two-Speed, Push Button Control | 
| NR3 | Transfer Case - All Wheel Drive (AWD), Open Diff., Single Speed | 
| NR4 | Transfer Case - Four Wheel Drive (4WD), Open Diff., Two-Speed | 
| NR6 | Transfer Case - Four Wheel Drive (4WD), Open Diff., Two-Speed, High Ratio |