Steering and Suspension diagnostic tips

Think that your steering and suspension might be the cause of your vehicle problems?

Here are some quick tips:

Test on the ground.

Shake the steering wheel quickly, turning it left and right ninety degrees. There should not be excessive play or knocking noises. If the car has power steering, do this with the engine running. 

Test in the air.

Hang the suspension, raise the vehicle so that it hangs freely on a lift or jacks approved for the weight of the vehicle. With weight off the suspension, check each part for looseness, excessive play, damage, cracks, broken boots, or any other clues.

Check the fluid.

Fill fluid reservoir to manufacturer specifications.

For vehicles equipped with power steering that use power steering fluid, check to see if the fluid reservoir is full. If it isn’t, fill it to manufacturer specifications, and then check again after a while. If it has gone down again, check under the vehicle for signs of any fluid leakage. Leaks could potentially be in the steering pump, hoses or the steering rack itself. After filling, turn the steering wheel to the left and right three times with the engine running to get air out of the system.

Scan tools and advanced diagnostics.

You can effectively test the CAN bus steering angle sensor by following a few quick steps:

• Use a scan tool to monitor chassis-related PIDs.
• Use a lab scope to monitor high-speed bus activity when the steering wheel is turned. You should see an increase in bus traffic as the steering wheel turns. The two scope leads are connected between ground and the CAN hi and CAN low circuits. 
• You can use a scan tool to reset the steering angle sensor after replacement of the steering column and various other steering components, including the sensor itself. In some vehicles, this is required after a battery power loss as well.