I recently started having issues with my TCU caution staying on constantly, not flashing even though the waste gate tested correctly each time I turned the master on and I observed the movement. The other day when I turned the master on it didn’t test correctly so I shut the master off and then back on and it then tested correctly so I started the engine and  now the master warning light and caution started flashing so I shut the engine off. Now when I turned the master switch back on the waste gate didn’t test and there was a loud solenoid type clicking noise. I have tested the throttle position sensor with the new Buds software and tested it also with the continuity tester and it appears to have tested ok and I can slightly move the waste gate so it doesn’t appear to be frozen so I’m thinking there is something binding perhaps at the servo or cable. This airplane sat in an unheated hangar from January until June when it was flown from VA to NH without any problem, any ideas.


  • Re: TCU flashing caution &warning lights

    by » 8 months ago

    Hello Robert

    There should be 2 lamps wired into the system, a RED and an ORANGE.  The red lamp is solid red in the case of overboost and blinking red in the case of overspeed, both are serious.  The orange, caution, lamp is for everything else.  A blinking lamp is a failure of one of the sensors.  The heavy maintenance manual gives you all the tests for each one.  In the TCU program you should be able to see the faults and which one it was that is causing the problem.  If you have checked the wastegate and are not getting a failure in that is cycles and you have normal boost pressures then look at the other sensors in the system.  (temp sensor, pressure sensors, etc) 


You do not have permissions to reply to this topic.