Dorman 599-105 Transfer Case Control Module

Transfer Case Control Module Replacement

Restore transfer case operation with this Dorman transfer case control module. Part number 599-105 is a direct replacement for specific GM trucks and SUVs with push-button 4WD, helping return electronic transfer case control to normal function.

• Replacement transfer case control module for vehicles with RPO code NP8
• Orange connector color with pin terminal type
• Matches the function and performance of the original module on listed applications
• Fits select Cadillac, Chevrolet, and GMC 4WD models with 2-speed push-button shift transfer case
• Package contents: transfer case control module

Detailed Product Overview

Dorman 599-105 is a transfer case control module built for specific GM applications where the original module is no longer controlling the transfer case correctly. It is used on 1999-2002 Chevrolet Silverado 1500, 1999-2002 GMC Sierra 1500, and related Cadillac Escalade and GMC Yukon applications equipped with RPO NP8. This module is a practical OE-style replacement for restoring electronic shift control in vehicles with a 2-speed push-button shift transfer case.

This part cross-references Cardone Reman 73-42104 for the same application.

Common Problems This Part Can Address

• Inoperative push-button 4WD shift commands
• Transfer case not responding to mode selection
• Intermittent or failed electronic transfer case control
• Loss of normal 2-speed transfer case operation on NP8-equipped vehicles
• Faulty original module on GM trucks and SUVs

Installation Notes and Fitment

Compatible with 2002 Cadillac Escalade, 2002 Cadillac Escalade EXT, 2002 Chevrolet Avalanche 1500, 2002 Chevrolet Avalanche 2500, 1999-2002 Chevrolet Silverado 1500, 2001-2002 Chevrolet Silverado 1500 HD, 1999-2002 Chevrolet Silverado 2500, 2001-2002 Chevrolet Silverado 2500 HD, 2000-2002 Chevrolet Suburban 1500, 2000-2002 Chevrolet Suburban 2500, 2000-2002 Chevrolet Tahoe, 1999-2002 GMC Sierra 1500, 2001-2002 GMC Sierra 1500 HD, 1999-2002 GMC Sierra 2500, 2001-2002 GMC Sierra 2500 HD, 2000-2002 GMC Yukon, 2000-2002 GMC Yukon XL 1500, and 2000-2002 GMC Yukon XL 2500 with RPO code NP8.

Verify the vehicle’s RPO code NP8 and connector style before ordering. The orange connector and pin terminal layout should match the original module on the vehicle. Professional diagnosis of the transfer case system is recommended before replacement.

Quality Assurance

Dorman designs replacement electronic components to provide the same function and performance as the original part on the listed vehicles. Part number 599-105 is built for direct-fit service on confirmed NP8-equipped GM applications.