steering service light came on 2004 Pontiac Grand Prix

On one my customers 2004 Pontiac Grand Prix, The relatred problem was noticed.

In his case abs and traction control started shuting off while driving and steering got tight.

In this case we tried the following procedure to resolved the issue.

The details we tried are as follows :-----

First thing to check  is fuse box,inspect the  bottom right 3 fuses in the fuse box box under hood, in our case we  noticed that one of the bottom 3 fuses was cocked slightly to side and sure enough was loose, just pushed them all back down (NO NEED TO FORCE AND PUSH HARD OR WIGGLE AND PLAY WITH THEM YOU'LL KNOW IF LOOSE JUST LIGHT PUSH)
This solved the issue.Till date  no more messages and can turn traction control off and on with no issue. 

So in your case also try this procedure and see if that helps.

But if this is not in your case.

Then on case of this steering service light came ON./

Problems 

The problem is likely the pump but there is a sensor that adjusts the pressure that the pump supplies to the steering gear and that could also be the problem. The use of a Tech II scan tool should be able to tell if the pump is putting out pressure and if it is not the pump is bad. The Tech II is a tool that most any dealer would have and some independent garages may also. These have a high failure fate of the pump shaft and if you remove the belt and pull the pulley on the power steering it may pull right out if it does the pump needs to be replaced.
Basically when the power steering pressure sensor does not detect pressure it would likely to that light on, or the problem could also be the sensor itself (this is not a common problem).
Also the steering rack and pinion needs to be inspected.

This details will help.

Thanks.

See the recommend help solution showed below :----

Steering service light ON GMC Sierra Denali?

http://technoanswers.blogspot.in/2012/02/steering-service-light-on-gmc-sierra.html