Truck Trend Garage: What Is Electric Power Steering (EPS)
Q: While reading the article in your March/April issue, it speaks of the 2014 Sierra and Silverado pickups having electric power steering. Just what is this and how does it work without a hydraulic pump?
A: That's an excellent question! EPS (electric power steering) systems are being applied to new vehicles at a fast rate. The foremost reason is the increase in fuel economy by eliminating the power-robbing hydraulic power steering pump revolved by the engine's drive belt. And no, this is not steer-by-wire; the steering wheel is still physically connected to both front wheels.
An EPS steering rack (gear) is basically a standard rack-and-pinion, only now powered by an integral electric motor. The steering sensor mounted at the rack detects driver input at the steering wheel, while the EPS control module uses this and other data such as vehicle speed to tailor fit the amount of steering assist. This provides advanced control that wasn't possible with hydraulic power assist, to adapt steering and handing to driving conditions. I've seen very few problems with the systems currently on the road, and the discontinuation of the hydraulic power source eliminates the inevitable noise and leaks. Plus the EPS system involves less bulk and weight. I don't see any cons.
| Electric Power Steering
How To Reach Alex
If you have a technical question regarding your pickup, SUV, or van, feel free to contact Alex, a master technician with the National Institute for Automotive Service Excellence. Send a letter to him in care of Truck Trend Garage, 831 S. Douglas Street, El Segundo, CA 90245, or e-mail us at trucktrend@sourceinterlink.com. Please include the VIN with your question. Due to the volume of questions received every month, we cannot guarantee that everyone's question will be personally answered or will appear in the magazine.
Can't wait for help with a problem you're having with your Truck or SUV? Ask the expert we trust here at Truck Trend Garage -- visit Alex Steele at www.RealWorldAutomotive.com.
