Sienna LE V6-3.0L (1MZ-FE) (1998)
Test conditions:
^ Running engine at idle speed
^ Front A/C and rear A/C blower switches at "HI" position
^ Front A/C and rear A/C temperature control dials at "Max. COOL" position
^ A/C switch ON
^ Set manifold gauge set
^ If the circuit is as specified, try to replace the amplifier with a new one.
^ If the circuit is not as specified, inspect the circuits connected to other parts.