+1 on the shutoff actuator (has a brown hose going to it).

It "hooks" onto the rack and moves it to zero fuel position to stop the engine. If you put it back in wrong it jams the rack in max fuel position. When you go to restart the engine the rack is stuck on max fuel, and there is nothing you can do to stop it before catastrophic failure.

If you do remove this device, when you reinstall it, be prepared to have a swift way to deprive the engine of its fuel or air before restarting the engine. Best way is to have a large piece of wood ready to slap over the air intake. The 606 IP does not have an emergency stop lever like the 603 and 61x IPs. (Even if it did, the rack is jammed so it would be useless anyway in this circumstance.)

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech