[derekoh]

I am getting this code before and after the turbo was replaced. The truck has no bottom end power and is very jerky boost pressure the higher the boost gauge goes. Its an early build 03.

 

[MikeL46]

I couldn't find any reference to P0046. Could it be something else?

Mike

 

[derekoh]

I found the Fault Code Diagnostics from International and they say...."Code P0046 is set when a short to ground, open, or short to power is identified in the VGTCV or wiring between the PCM and VGTCV. This circuit is a continously monitored circuit that takes less than one second to set."

 

[jimmy]

Sounds like a chafed harness issue ground the VGT solenoid which would make turbo do full then low then full boost.
Inspect wiring from VGT solenoid at top of turbo through any close to metal areas. Also look under air cleaner and on driver's side inner fender.

 

[derekoh]

I will have to check all that....hopefully its that simple. The turbo I took off has a different part number than the one I put on, but I guess its an updated 03 turbo. It still whistles like the old one, but everything is very sluggish to respond. I think I am going to check the wires and smoke it to see if there are any leaks.

 

[derekoh]

The other thing that I notice is that it sounds like there is a bird chirping since I have replaced the turbo. It only happens when the truck comes back down to idle.

 

[derekoh]

I replaced the vgt solenoid and the truck was no better. I took the truck to the dealer and they found out the egr valve was stuck half open. After they drove the truck they say everything is good. My question....do you think the stuck open egr valve or the vgt solenoid is to blame for the turbo failing? Or is the turbo going out to blame for the other two going out? The dealer also said they sell a cleaner to clean the intake of carbon....should I do this?

 

[derekoh]

Well after the turbo, vgt solenoid, egr valve, and intake air temperature sensor i still dont have the truck fixed. The biggest thing I have noticed now is that its not cycling the egr like it used to. Before I could hear the distinct exhaust tone and then it would cycle and all you could hear was the wistle. Now I can hear the exhaust tone, but when it tries to cycle to the turbo whistle you can hear the engine change tones, but no whistle. Any ideas?

 

[teamroper60]

It sounds to me like you are not getting power to the VGT solenoid. Did you check the wiring harness to the VGT solenoid?? If there is no power to that solenoid, the vanes will default to wideopen, which would mean no whistle and no power at low speed.

 

[derekoh]

I have checked around the plug and down around bottom of turbo. Its hard to trace it after that. I will keep looking. Thanks for the help. Could it be a y-pipe thats cracked. I am not sure what process is going on when the exhaust not changes from rumble to whistle.

 

[teamroper60]

It isn't changing from the "rumble to whistle" because the vanes are not moving to the "closed" position. The VGT solenoid moves the vanes. I still believe your issue is related to a lack of power to the solenoid. Since the solenoid was changed and the turbo was changed, we can presume that the turbo's vanes are not stuck and the solenoid is good. This leaves us with either an electrical issue (wiring to the solenoid) or oil supply issue (the solenoid uses oil to actuate the lever that rotates the vanes).

 

[derekoh]

When you say oil issue.....what can I check? I have noticed that when I try to accelerate when the truck is taking off from a dead stop or when you are on the highway doing 65 it will build boost VERY slowly. So slow that the EGT's will run up past 1000-1100 if I stay in it.

 

[derekoh]

I took my truck in to the dealer and they said the egr valve was stuck open and the intake needed cleaning. I bought the egr valve and they gave me carb cleaner to spray into the intake (which didn't help). I put the egr valve in and the truck is still running the same. It has more top end power, but the low end is very sluggish. Would the intake cause all of this (turbo, vgt actuator, egr valve)? The truck keeps getting a little better each time. I did have some posts about a vacuum cleaner sound coming from near the turbo (which is gone now) when you got up to 7psi of boost. I lost the turbo pulling the camper, but even with the new turbo I am still back to the same symptoms I was having before. Low boost on takeoff until I hit second gear and then boost returns and builds to 25psi. When I get out of the throttle and just let it get into overdrive on the highway I cant hardly build boost. It will jump to 10 or 15psi, but then the EGT's are getting high if I keep trying to make it build boost.