Engine Shutoff Procedure (emergency procedures)
From OCE Space Simulation
Emergency Shutoff Procedures
Should the mission commander or flight director determine that a manual shutoff of the engines is required, the following procedures are to be followed.
Send an astronaut on an EVA to access the hatch located behind the engineering closet. There is a large red on-off switch with a number pad located below the switch. To shut off engines, type the code 549271 into the num pad, and the turn off the engines.
Reactivation of Engines
To turn the engines back on after an emergency, simply use the code 337412, and turn the switch back on. This should restart the engines if no external factors are in play.