I was reading thru the other thread and learned about the variable steering assist. My 99EB had air suspension that was removed before I bought the truck. It also has what I consider to be the most light, sensitive, fast-ratio steering of any vehicle I've ever driven. Is this because the air suspension was removed and it has defaulted to max assist? I've gotten used to driving it this way, but if there's a way to make it more "normal", that would be a plus.

I know with many of the GM Autorides, putting a resistor across the old shock wiring harnesses fools the BCM into thinking the factory suspension is still in place. Is that something I can do with the Expy?

And yes, the check suspension light is on all the time.

 

When traveling down the road, the air suspension system keeps the solenoid open which allows the air to move back and forth between the rear air bags. This makes for a smoother ride, as for example, say the right rear wheel hits a bump in the road. With the solenoid open the right rear wheel can come up over the bump easier as the air in the bag just blows over to the left rear bag.

But if you make a sudden evasive maneuver, the SAS detects the sudden movement of the steering wheel. Say you suddenly swerve left. The solenoid closes to isolate the two air bags. If it didn't, the truck would heal over (think Greyhound bus) and be hard to control when at speed. With the solenoid closed, the vehicle remains flatter, as the isolated air bags are then acting like a super duty rear anti-roll bar, yet the suspension is supple when driving normally.

When the air suspension light is on, the air suspension system is off and the solenoid remains open all the time. It makes the steering feel extra light as there is very little anti-roll bar effect. (Scared the bejabbers out of myself one time when I forgot to turn the air suspension back on (after being on the hoist) and a deer ran out in front of me. Thought I was gonna roll it!)

 

There is no more air suspension

 

My '02 Navigator had the same issue, the power steering felt like it was full assist all the time. What ended up being the problem with mine was a plug was disconnected on the power steering pump under the car. I noticed it when I was changing the oil. The harness is right next to the oil filter. Somehow it got unplugged and was just hanging. After plugging it back in, its working normally and steering is heavy at speed and light when stopped. Who know how long it was like that, I found it shortly after I bought the truck last year while changing the oil.