Charge Warning Light Comes ON while Driving

WARNING: This page is about a different car, the 2006 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.

CHECK LOCK FUNCTION OF CLUTCH PULLEY
1. Check the lock function with the pulley installed in the vehicle.
  1. Visually check that the rotor in the generator operates with the engine started.
2. Check the lock function with the pulley removed from the vehicle.
  1. Remove the generator pulley cap. Using SST, hold the generator rotor.
  2. Turn the clutch pulley clockwise and check that the outer ring locks.
    OK: The outer ring locks.
    
    Fig 1: Checking Lock Function Of Clutch Pulley
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    SST 09820-63020
NG : REPLACE CLUTCH PULLEY

OK : GO TO NEXT STEP
CHECK LOCK OF CLUTCH PULLEY
1. Start the engine and visually check looseness of the clutch pulley.
  OK: The clutch pulley is not loose.
NG : TIGHTEN CLUTCH PULLEY TO THE SPECIFIED TORQUE

OK : REPLACE GENERATOR ASSEMBLY