Delphi’s new four wheel steering system, ‘Quadrasteer’, which debuted on GMC Sierra Denali full size trucks this year, will now be available in the 2002 calendar year on GMC Sierra and Chevy Silverado 1/2 ton, extended cab short box trucks.

In addition, 2003 models with optional Quadrasteer include Chevrolet Silverado and GMC Sierra 1500HD short box crew cabs and Chevrolet Suburban and GMC Yukon XL 3/4 ton full-size sport utility vehicles.

“We are very pleased to see Quadrasteer available across more vehicle platforms at General Motors,” stated Paul J. Tosch, president of Delphi Saginaw Steering Systems and vice president of Delphi Automotive Systems. “Full size SUVs are the next logical step for vehicles which will benefit from this revolutionary system. Quadrasteer will enhance their consumer value through the added maneuverability and stability as seen now on the Sierra Denali.”

Quadrasteer combines conventional front-wheel steering with an electrically powered rear-wheel steering system. The system has four main components — a front-wheel position sensor, steerable solid hypoid rear axle, electric motor-driven actuator, and a control unit. Handwheel position and vehicle speed sensors continuously report data to the control unit, which in turn determine the appropriate angle of the rear wheels. Algorithms are then used to determine the correct phase of operation.

The system operates in three principal phases: negative, neutral, and positive. At lower speeds, the rear wheels turn in the opposite direction of the front wheels. This is the negative phase. At moderate speeds, the rear wheels remain straight or neutral. At higher speeds, the rear wheels are in the positive phase, turning in the same direction as the front wheels.