Why is electronic push button four-wheel-drive (4WD) disabled when my ABS module is removed?
The ABS module runs a different anti-skid program when the vehicle is in 4WD. Certain vehicles also use information from the ABS module; such as front and rear wheel speeds to operate the “automatic” 4 wheel feature. If the module is removed or completely powered down, the transfer case control unit will disable itself and 4WD. Where is the ABS controller located in my 1999-2003 GMC/Chevy truck? My Isuzu? My Honda? In most GMC and Chevy vehicles the ABS controller/computer (EBCM) is piggybacked with the hydraulic manifold attached to the vehicle frame on the driver’s side under the seat. It is outside of the cab in the dirt and elements, not inside. The ABS controller is the black plastic module with the aluminum lid. It is bolted to the top of the aluminum manifold which has the electric motor protruding from the side. You will see that the control module has three (3) wire harnesses plugging into it. One of these three (3) goes directly to the electric motor. For Isuzu and Honda vehi
