I have a schedule from the week of February 3 through 9th 2012.
Pixar Pals
Fri to Sun, Wed & Thur: Hollywood Blvd.
11:00AM, 12:00, 1:00, 2:25, 3:25 and 4:25PM
Not sure what the days or times will be when you're there. You'll just have to check online to see.
When we were there they came out and parked in the intersection by Aladdin's theater. There is yellow tape on the ground. The cart came out, parked in the far end of the area and the party began. The kids had a fun time with the characters.