Scion xb stall


have an 04 scion xb. very occaionally the engine stalls when I depress clutch to make a turn of a highway. usually durng hot weather.Left turn after 10 - 20 miles at 60mph turn on blinker, slow down a bit, depress clutch, the engine dies - all the dash lights come on, pop clutch or turn key to start, she fire sright up and goes fine.

Toyota says they dont have computer codes to indicate any problesm. its been checked several times.

??? any ideas