Chevrolet Cruze Repair Manual: Variable Effort Steering System Description and Operation
The Variable Effort Steering (VES) system or MAGNASTEER® varies the amount of effort required to steer the vehicle as vehicle speed changes. At low speeds, the system provides minimal steering effort for easy turning and parking maneuvers. Steering effort is increased at higher speeds to provide firmer steering (road feel) and directional stability. VES works in parallel with the base torsion bar in the power steering system.
The VES control module communicates on the high speed bus and uses vehicle speed and the steering wheel angle speed to command a current that is most appropriate for each speed to the VES actuator in the steering rack and pinion. The actuator is a variable electromagnetic actuator, which consists of one multiple-pole ring-style permanent magnet, with a pole piece, and an electromagnetic coil assembly on each side. By commanding currents between -3 to +3 Amps through the coils the steering effort will be adapted to the vehicle’s speed.
At lowest speed, around 5 km/h (3 mph) the coils are polarized in such a way that the magnetic forces are repelling each others and hardly any effort is required to turn the ring magnet between them.
At mid speed, around 70 km/h (45 mph), no current is sent through the coils and steering is assisted by hydraulics only. At high speeds the coils are polarized in such a way that the magnetic forces are attracting each others and high effort is required to turn the ring magnet between them.
The VES control module communicates on the HS GMLAN bus.
The VES control module has the ability to detect malfunctions in the actuator. Any malfunctions detected will cause the system to ramp to zero amps. Steering will be assisted by hydraulics only and a DTC is set.
Special Tools and Equipment
Power Steering System Description and Operation
The hydraulic power steering pump is a constant displacement vane-type pump
that provides hydraulic pressure and flow for the power
steering gear. The hydraulic power steering pumps are either belt ...
Steering Wheel and Column
Specifications
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Other materials:
Vehicle Certification, Tire Placard, Anti-Theft, and Service Parts ID Label
Vehicle Certification Label
The vehicle certification label is located on the driver door and displays
the following assessments:
Gross Vehicle Weight Rating (GVWR)
Gross Axle Weight Rating (GAWR), front and rear
The gross vehicle weight (GVW) is the weight of the vehicle and everything it ...
Loss of Control
Skidding
There are three types of skids that correspond to the vehicle's three control
systems:
• Braking Skid — wheels are not rolling.
• Steering or Cornering Skid — too much speed or steering in a curve causes tires
to slip and lose cornering force.
• Acceleration Skid — too much thro ...
Checking and Adding Power Steering Fluid
Caution: When adding fluid or making a complete fluid change, always
use the proper power steering fluid. Failure to use the proper fluid
will cause hose and seal damage and fluid leaks.
Clean the area surrounding the reservoir cap.
Remove the reservoir cap.
Inspect the power steeri ...
