Here's what I found.

"There's a TSB for it. "Cars built before 2/5/07 need a PCM reflash and should follow the TSB 18-003-07 procedure. - Cars built after 2/5/07 likely need a new actuator"

Then I found this: "the SRV solenoid houses a 3 circuit position sensor. just because the valve actuates, doesn't mean the PCM sees it."

This guys solution: "I pulled the actuator off and found the valve stuck so I kept working it till I guess I finally wore down whatever the valve was getting stuck on..... I havent had a code thrown for 2 days now."

I hope this helps. lxforums is the best place for finding solutions to 300 problems.

On the lights:

"There is a STAR case relating to steering shaft protrusion in relation to the ESP light coming on from SAS calibration. It involves removing the steering wheel & SCM (plastic collar containing clockspring, cruise switch, SCCM, Multifunction Switch and SAS)and measuring the shaft protrusion. But... you say it comes on when making left turns. I had an 08 with this exact same problem. Found the STAR case and saved some time. I didn't measure the column, but skipped ahead and just tried the repair procedure for if the column was ok. It worked. The procedure mistakenly instructs to use a T25 Torx screwdriver. You have to use a T30 Torx screwdriver, not a replaceable bit type. Here's the procedure:

Repair Procedure:

1. Through the hole in the bottom of the SCCM (refer to illustration) insert a T30 Torx driver and loosen the clamp screw approximately 4 turns. Do not remove the screw.
2. Pull the SCCM upward on the column tube toward the steering wheel as far as possible. The amount of movement is limited because the clamp screw is captured within an oval shaped hole in the tab on the casting of the column tube.
3. Re-tighten the screw.
4. Test drive the vehicle.

Les