L WING A/I PRESS HI
(Caution)

High pressure has been sensed in the left wing anti-ice system.

• High Pressure Sensor (HPS) No. 1 (MT19)
• High Pressure Valve (HPV) No. 1 (V5)
• Integrated Air System Controller (IASC1) (A55)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

The amber 'L WING A/I PRESS HI' caution CAS message indicates high pressure has been sensed in the wing anti-ice system.

• The IASC has determined that the associated wing system has been over pressurized detected by MT 19 or MT 20 through failure of the wing anti-ice valve.
• The high pressure transducers are found in the aft equipment compartment, downstream of the HPVs. The sensor is an gauge pressure transducer that can measure pressure from 0 to 75 psig (0 to 517.11 kPa). It is used to monitor the HPV output pressure.
• Normal regulated pressure is set at 36 psi.
• Check for MDC message 'L BLEED PRESSURE HI' under HI PRESS VALVE 1 to confirm fault.

1. 1. Swap HPSs.

      1. If system checks are good, do close out.
      2. If fault remains, continue with next step.

   2. Swap HPVs.

      1. If system checks are good, do close out.
      2. If fault remains, continue with next step.

   3. Swap IASCs.

      1. If system checks are good, do close out.
      2. If fault remains, continue with next step.

   4. Do wiring checks between HPS 1 and IASC1. Repair as required.
   5. Do close out.
      Select an MDC Fault Code/Message:B3-006843 - L BLEED PRESSURE HIGH [HI PRESS VALVE 1]