Power Steering went out!

I have a 97 Chevy 1500 Z71

So a few days ago I was driving and suddenly I had a heck of a time trying to turn the wheel. So I went and took it into the shop and they said it was the power steering pump. Well I have friends in town this weekend so I just wanted to get it done so I gave it to the shop to work on.

Well I drove off the lot and maybe about a 1/2 mile down the road the steering went out again. Then after I turn off the car again then back on it works for a short period then goes back out. So I am completely confused. Anyone have any suggestions?

Some have a sensor that reduces the steering assist on the highway, it's supposed to make it feel tighter or something. If yours has that, it's probably an issue with electronics.
Of course that's assuming you checked the P/S fluid after it gave out the second time and that the belt's still on there

I definitely have P/S fluid in there. Would it be the EVO sensor that you are talking about?

I definitely have P/S fluid in there. Would it be the EVO sensor that you are talking about?

Sounds right... I've never personally worked on one however.

Okay I just put a new EVO sensor on my car. Started it back up and when I got to about 20-30 mph it did the same thing! It started to become extremely difficult to turn.

So I just finally decide to try to drive without the sensor plugged in. Well it drives fine without it plugged in. What could this be!!!!!

Okay I just put a new EVO sensor on my car. Started it back up and when I got to about 20-30 mph it did the same thing! It started to become extremely difficult to turn.

So I just finally decide to try to drive without the sensor plugged in. Well it drives fine without it plugged in. What could this be!!!!!

There are 2 fuses involved in the system. 1) GAUGES fuse #4 10a (supplies ign power to the EVO/PASSLOCK module and 2) SECURITY/STRG fuse #21 20a supplies hot batt voltage to the module.

The components in the system are
1. VCM (sends the signal from the VSS (vehicle speed) to the EVO module)
2. Steering wheel speed sensor (commonly refered to as the EVO sensor) sends a signal to the EVO module.
3. The steering assist control solenoid located on the back of the pump. This is an eletronically controlled variable orfice (EVO) that controls the amount of pressure from the pump to the steering box as determined by the EVO/PASSLOCK module from the inputs from #'s 1 & 2 above.
4. EVO/PASSLOCK module. (the computer for the system).

You might start by replacing the #21 fuse (mentioned above) as it is dedicated to this system.

Beyond that, since this sytem is all electronic, you'll need to get it scanned for DTC's to be able to really pin point where the problem is. There are about 9-10 DTC's in this system all starting with "C" (Cxxxx).