550 Cat twin turbo low boost

Most trucks have a switch or button to get the flash code. Not sure how the Pete's work though.

Might let folks know what year your truck is. The procedure may have changed from one model to another.

 

With the cruise switch off hold up or down set cruise control switch for about 5 seconds and let go, the check engine lite will flash to sets if codes, example, flash 4 times then pause then flash 3 times. That give you the code which would be 4-3, you would look that code up. A 5-5 is normal and no codes.

 

I don't have the codes in front of me but you can google them once you find out which code you have.

 

Sounds like an intake actuator or the wire harness for the actuator. Just went through this on my 07 KW. They changed the actuator and that worked for three weeks then check engine came back on so they changed the harness and so far so good.

Same symptoms as yours. Would only build about 20 pounds of boost.

 

Here is a CAT Acert code list.

http://www.thetruckersreport.com/truckingindustryforum/attachments/catacert-txt.81586/