When a CAS message 'SPLRS/STAB BIT', 'STAB CH1 FAIL' or 'STAB CH2 FAIL' is posted during the ground power-up:

1. Ensure the circuit breakers (CB's) 'FLT CTL1 CH A', 'FLT CTL1 CH B', 'FLT CTL2 CH A' and 'FLT CTL2 CH B' are 'IN' on the Electrical Management System Control Display Units (EMS CDU).
2. Pressurize all hydraulics systems (1-2-3) and wait until the 'SPLRS/STAB IN TEST' advisory CAS message is posted and clears.
3. Wait 30 seconds after the CAS message 'SPLRS/STAB IN TEST' clears. (Reference AMM TASK 27-61-05-740-801 - Flight Control Unit (FCU) System Power On Self Test(SPOST).
   NOTE: Make sure no flight control surfaces are moved and no flight controls switches are selected in the flight compartment during the built-in-test.
4. If the message remains posted, select 'FLT CTL1 CH A', 'FLT CTL1 CH B', 'FLT CTL2 CH A' and 'FLT CTL2 CH B' CB's to 'OUT' on the EMS CDU.
5. If the CAS message is a SPLRS STAB BIT or related to the pitch Trim system, cycle the AC thermal circuit breakers of the STAB CH1 PWR and STAB CH2 PWR.
6. Wait 30 seconds and select the flight control channel CB back to 'IN'.
7. Pressurize all hydraulics systems (1-2-3) and wait until the 'SPLRS/STAB IN TEST' advisory CAS message is posted and clears.
8. If the CAS message doesn't clear, repeat this FCU CB out / in procedure again.

   1. If the fault clears after any of these steps, then the system is fully functional.
   2. If the fault remains active after performing the above reset procedure five times, perform a complete shutdown of the Aircraft then try the test again.
   3. Otherwise, troubleshoot the fault.
      
      
      NOTE: To minimize waiting time prior to departure, Bombardier suggests this alternate procedure, prior to passengers boarding:

• Power-up aircraft with Ground Power Unit (GPU) or with one engine.
• Pressurize all 3 hydraulic systems, and FCU will initiate self-test.
• If SPOST 2 failed, follow reset procedure as mentioned in the above steps.
• Once the FCU passes the SPOST2 BIT Test without nuisance CAS messages, maintain aircraft AC power ON using the GPU or APU source. Turn off non-essential hydraulic systems. This procedure will prevent the initialization of an FCU SPOST2 BIT test following the next engines start.