On-Vehicle Inspection

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.

CHECK V-RIBBED BELT
1. Check the belt for wear, cracks or other signs of damage
  If any of the following defects is found, replace the V-ribbed belt.
  
  HINT:
  - The belt is cracked.
  - The belt is worn out to the extent that the cords are exposed
  - The belt has chunks missing from the ribs
  Fig 1: Checking V-Ribbed Belt For Wear And Cracks
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check that the belt fits properly in the ribbed grooves.
  HINT.
  
  Check by hand to confirm that the belt has not slipped out of the grooves on the bottom pulley. If it has slipped out, replace the V-ribbed belt. Install a new V-ribbed belt correctly.
  
  Fig 2: Identifying Proper Position Of V-Ribbed Belt
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002