Hi all,On a flight yesterday I loaded up the sim at CYCC; turned the plane on, got the IRS working and this was the Captains ND:No failures active, as you can see:The terrain on the FO's display was on and off, too..I have video if anyone wants..As you can see, I treated it as a real failure and used the lower DU. It went away after a reboot..Any ideas?bestjake

it seams like the Left IRS has a fault (it's no failure just a fault) , As you can see there is no HDG/TRK information on the capt PFD/ND. That is why the amber MAP failure flag is showing on ND because the L FMC can not display the information on the ND when it doesn't know the correct heading/Track.If you go to the ISDU (IRS Display unit) on the AFT overhead panel and set the system selector to -L- and the System Display selector to HDG/STS (Heading/Status) and check if there is a maintenance code. Most of these faults can be cleared by switching OFF the applicable IRS wait for the ALIGN light to go out and then reALIGN the IRS. Only perform this when at the gate and parking brakes are set.When in the AIR and the IRS gives a faulty information leave the applicable IRS ON, Just set the IRS Select Switch on the FWD overhead panel to the correct functioning IRS in your case to the Right IRS.