2005 Mack e7 turbo speed code

[Farmermechanic]

I have a 2005 Mack ch600 truck with a e7 that has the air operated vgt turbo. Truck came in with egr codes and turbo speed code. Flash code 6-2 egr got deleted but still can’t get rid of turbo code. Replace speed sensor and checked wiring and replaced ecm still not working. Any ideas would help a bunch 

[Joey Mack]

Did you look inside the speed sensor hole while turning the propellar to look for damage, or soot? I havent been in one of these is many years. I have the V-MAC III book, so later on I can look at the flow chart for a 6-2 code.

[880joe]

Does the little spin on air filter on the left side of the engine have anything to do with the turbo? If so has it been changed?

[Joey Mack]

That filter is for the VGT actuator.  I have seen them restrict or stop air flow many times. 

[fjh]

So investigate this! On startup turn the key on observe the pistion on the VGT !  Is the vgt doing its self check? Is it going full stroke ? If it does not stroke out both directions it may be that the vanes are sticking and not allowing the turbo to regulate properly!