Dorman 599-104 Transfer Case Control Module

Transfer Case Control Module for NP8 Systems

Restore transfer case operation with this Dorman transfer case control module, part number 599-104. It is a direct replacement for specific GM trucks and SUVs equipped with the NP8 2-speed push-button shift transfer case, including Cadillac Escalade, Chevrolet Tahoe, GMC Yukon, and select K1500/K2500 applications.

Built to match the original module’s function and performance, this replacement helps bring back reliable electronic transfer case control without replacing the entire system.

Key Features

• Replacement transfer case control module for NP8 2-speed push-button shift systems
• Orange connector color for application-specific fitment
• Pin terminal type for factory-style electrical connection
• Includes the transfer case control module only
• Dorman 599-104 for direct-fit service on select GM 4x4 vehicles

Detailed Description

Dorman 599-104 is a transfer case control module replacement for vehicles that rely on electronic shift control to manage 4WD operation. It is engineered to provide the same function and performance as the original module on specific applications, making it a practical solution when the factory unit is no longer controlling the transfer case correctly. This part cross-references ACDelco 73-42103 and 12577421 for the same application.

Compatible With 1999-2000 Cadillac Escalade, 1998-2000 Chevrolet Tahoe, 1998-2000 GMC Yukon, 1998-1999 Chevrolet K1500, 1998-1999 Chevrolet K1500 Suburban, 1998-1999 Chevrolet K2500, 1998-1999 Chevrolet K2500 Suburban, 1998-1999 GMC K1500, 1998-1999 GMC K1500 Suburban, 1998-1999 GMC K2500, and 1998-1999 GMC K2500 Suburban with RPO Code NP8 for the 2-speed push-button shift transfer case.

What It Can Help Solve

• Loss of electronic transfer case shift control
• Intermittent or nonresponsive 4WD mode selection
• Transfer case control module failure on NP8-equipped GM vehicles
• Problems restoring factory push-button shift operation
• Need for a cost-effective replacement versus full system replacement

Installation Notes and Tips

Verify the vehicle’s RPO Code NP8 before ordering. Confirm connector style, terminal type, and application details against the original module to ensure proper fitment. After installation, follow the vehicle’s service procedure for system checks and any required transfer case relearn or calibration steps.

Quality Assurance

Dorman replacement electronic components are built to match original function and performance on the listed applications. This part is intended for direct replacement service on the specified Cadillac Escalade, Chevrolet Tahoe, GMC Yukon, and related GM truck models.