Just had the z06 out for a cruise and suddenly the steering got extremely stiff to turn. I pulled over and check my tires and power steering fluid, all looked ok. How do i determine if its my pump or the sensor. No signs of a bad belt or leakage or noise. I assume there is only one serpentine belt.

 

At what speeds did you notice the steering get stiffer? If it happened at low speeds it could be due to a problem in the VES. If it is through the speed range then it probably is something else. Here is the VES description.

Variable Effort Steering System Description and Operation
The Variable Effort Steering (VES) system, or MAGNASTEER II® varies the amount of effort required to steer the vehicle as vehicle speed changes or lateral acceleration occurs. At low speeds, the system provides minimal steering effort for easy turning and parking maneuvers. At high speeds, the system provides firmer steering (road feel) and directional stability. When the system senses lateral acceleration, steering becomes firmer to reduce oversteering. The Electronic Brake Control Module (EBCM) controls a bi-directional magnetic rotary actuator located in the steering rack and pinion. The EBCM varies the steering assist by adjusting the current flow through the actuator. The actuator adjusts the amount of power steering assist to achieve a given level of effort to steer the vehicle. The VES system accomplishes this by adding or subtracting torque on the input shaft to the rack and pinion. The main component of the system is an electromagnetic actuator, which consists of a multiple-pole ring-style permanent magnet, a pole piece, and an electromagnetic coil assembly. The VES system uses the Antilock Brake System (ABS) wheel speed sensor inputs to determine vehicle speed. When the EBCM senses vehicle speed, it commands a current to the actuator that is most appropriate for each speed. The system also uses inputs such as Handwheel position, wheelbase, understeer coefficient and steering ratio to calculate lateral acceleration. The EBCM commands current from negative two amps to positive three amps to the actuator, which is polarized. At low speeds, a negative current is commanded, which assists steering. At medium speeds, no current is commanded and steering is assisted by hydraulics only. At high speeds, a positive current is commanded, which creates steering resistance. Ignition voltage and ground are provided through the EBCM. The EBCM has the ability to detect malfunctions in the actuator or the circuitry to the actuator. Any malfunctions detected will cause the system to ramp to zero amps and steering will be assisted by hydraulics only.

Bill

 

It's definitely noticeable at low speeds....haven't driven it that much since it happend...of course at higher speeds I'm not making as much of a turn on the wheel so I'm not sure, Maybe I'll take it out today and test it. If it is the VES whats next?

 

I checked fuses, nothing bad. So i took it out for ride to see how it drove at different speeds. Once i was able to get out of the driveway and neighborhood, at driving speeds it pretty close to normal...so I thought I'd take it for "spirited" highway run. When I pulled off at the offramp....all seemed fine steering was good froma stand still. I decided to test the abs, it worked fine. Pulling into the driveway and garage, back to normal.....so what's going on?

 

Try bleeding the system. It is not very difficult at all. Jack up the front of the car (wheels off of the ground) remove the cap from the power steering res. Make sure that the level is good.

Engine OFF; Key ON crank the wheel from full lock to full lock 20 - 25 times. Have someone watch the level in the PSP res. and add fluid as needed.

Start the engine and repeat the above procedure of lock to lock 20 - 25 times. Add fluid as needed.

 

I might give that a try if the problem comes up again. Is it possible it is related to sensing wheel speed or something like that. The reason I ask is, I don't think my traction control is working the same as it use to, it comes on, but after a hell of alot more wheel spin. Last week I left my lights on and completely drained my battery...when I got home I jumped it off another battery, rather than grounding the black lead I went to the neg. terminal for both jumping and later put it on a charger. Could that have done something electriacally? It's not like the problem immediately appeared after i started it, but with in a few days.
Is there anyway to check the traction control for proper operation?

 

This is excellent but I don't believe all years have the VES system!

What is the VES system code to see if one has this or not?

As for your problem, is it possible that you have a loose connection?

Have you ran the code check to see if any are present?

This will enable us to look in our manuals to find the proper fix. Check the codes becasue now I'm real curious as to your problem!

Thanks,Matt