cat acert vva operation

The way these vva's operate is simple but how does ecm determen what cylinder is not responding. I just learned that when the ecm activates a cylinder to operate and that cylinder doesn't the ecm knows because there is no spike in oil pressure that the vva oil pressure sensor is looking for. I thought this would be a good thread for all of us to teach and learn about cats vva's.

 

Yes you are correct! I just learned this. There is no documintation on this. The only documintation is in cat manual on operation. There use and how they work not how ecm looks at it. The vva solnoid is opened for oil to get to vvas. The oil is always there for jakes. I also learned when they first came out that they only operate under a load. Thats why if a vva is unhooked or bad it may take 8 hours for ecm to figure it out. I have talked to cat tech for east coast and he said they are supposed to let more air into cylinders under load and from his resurch thats why they added thr twin turbo system. He also said that it's based from miller cycle but cat willn't say this or take claim to that.