VNT Actuator (ALH)

Vacuum operated turbocharger diaphragm (ALH only).

Also called the VNT actuator, these tend to deteriorate with rusty housings and damaged diaphragms. This will cause poor turbocharger performance, in some cases owners have had their turbocharger replaced all due to this part causing the problem. It may move freely but could still be a source of a problem due to a damaged diaphragm. If you have been getting check engine lights and repeated activation of "limp mode" then it is possible your actuator is damaged or seized. On a cool engine, reach in behind the intake manifold and locate the actuator, if you can't move the actuator connecting rod by hand then you have a problem with yours or it could be a seized VNT section in the turbo.