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Discussion Starter #1
Looked it up and it seems either the turbo vanes are sticking or the position sensor is going bad.

Appreciate any tips on how to check either. I have an autocal but was thinking if the sensor is failing it could still be telling me the vanes are not moving. Right or wrong?

Boost still seems fine, running between 20-25 under moderate or heavy acceleration hauling the 5er.
 

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Discussion Starter #2
I should add, that this is the second time for the same code. First was on an rv trip, so I cleared the code and ran the truck through its paces, turbo wise. Hard acceleration, getting short boost to 20-22 psi and heavy decel using exhaust brake. My thoughts were hard accel to get vanes to full open and heavy decel for turbo brake to get them fully closed.

I do have efi on it, with turbo brake.

Suggestions? Is this hard to trouble shoot?
Thanks
 

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Discussion Starter #4
Ok thanks. I did search the code here and none of the thread titles even seemed related, but obviously there were threads on it.

This looks like a big job. I need to see how accessible the vps and solenoid are. Feeling very under the weather currently, so that does not help much either.
 

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Here is what you might look at:


Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.



  1. Ignition OFF, for 90 seconds, disconnect the harness connector at the TC control solenoid.
  2. Connect the J 34730-405 between the high control terminal A and the low control circuits terminal B.
Important: When the engine coolant temperature is less than 70°C (158°F), the test lamp will change brightness when commanded with a scan tool. When the engine coolant temperatures are above 70°C (158°F), the test lamp will flash ON and OFF without commands from a scan tool.



  1. Engine running, engine coolant temperature (ECT) sensor 1 must be less than 70°C (158°F). Command the TC Vane Pos. Ctrl. solenoid ON and OFF with a scan tool. The test lamp should illuminate and change from bright to dim when changing between the commanded states.
    • If the test lamp does not illuminate, test the low control circuit terminal B for an open/high resistance or a short to voltage. If the circuit tests normal, test the high control circuit terminal A for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM.
    • If the test lamp remains illuminated, test the low control circuit terminal B for a short to ground.
Important: The resistance of the TC control solenoid will vary with the temperature.



  1. Ignition OFF, measure the resistance of the TC control solenoid. The reading should be between 3-7 ohms.
    • If the resistance is not within the specified range, replace the TC control solenoid.
  1. Test for infinite resistance between each TC control solenoid terminal and the TC control solenoid housing.
    • If less than infinite resistance, replace the TC control solenoid.
  1. Disconnect the harness connectors at the ECM, and TC vane position sensor.
  2. Test for less than 5 ohms on all circuits between the following terminals:
    • The ECM C1 TC solenoid high control circuit terminal 48 to TC control solenoid terminal A.
    • The ECM C1 TC solenoid low control circuit terminal 96 to TC control solenoid terminal B.
    • The ECM C1 TC sensor signal circuit terminal 20 to TC position sensor terminal B.
    • The ECM C1 TC sensor low reference terminal 63 to TC position sensor terminal C.
    • The ECM C1 TC sensor 5-volt reference terminal 13 to TC position sensor terminal D.
    • If greater than the specified range, repair the high resistance in the affected circuit.
  1. Connect the ECM connectors. Test the TC vane position sensor.
  2. Install and connect the TC vane position sensor.
  3. Command the turbocharger TC Vane Position Sensor from 0 percent to 100 percent while observing the TC Vane Position Sensor Volts parameter. The voltage should increment smoothly and gradually from approximately 1.0 V at 0 percent to greater than 3.5 V at 100 percent.
    • If the voltage parameter does not change gradually and smoothly, replace the TC control solenoid.
  1. Inspect the turbocharger for debris, damage, or sticking vanes.
  2. If all circuits, the TC control solenoid, and the TC vane position sensor tests are normal, replace the turbocharger assembly
 

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Discussion Starter #6
Sadly this looks like its getting above my level pretty quickly.
 

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You absolutely need a very competent tech doing all the checks necessary to ascertain to a certainty what and where the problem is before replacing any parts. Many people have reported having their trucks 'fixed', paid a goodly sum for the fix, only to find that their trucks really aren't fixed.

If you follow the prescribed sequence of operations outlined in my previous post, many of they tests are quite simple and can be done with a simple volt meter and do not require an expensive tech. Some may be beyond your capabilities or desire to learn to do the tests. You will have to decide which is best in your situation.
 

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Discussion Starter #8
Yea thanks. There is inly so much I can follow and there is a great shop where the tech guys is very knowledgable and they are fair in pricing.

Might give em a call tomorrow.

I appreciate the info but as I said, I see this gettin above my pay grade as they say.
 

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I was breezing around ether-space the other day and I came across this stuff. It made me think of this thread.

Revive Turbo Cleaner.

Not horribly expensive and the reviews seem to be good, but who can trust that sort of thing. If it were me I might spend the $50 to see if it helped, thinking it most likely could not hurt.

Just a thought. Perhaps someone here has tried it and can chime in.

https://www.google.com/search?q=Revive+Turbo+Cleaner+Starter+Kit+Turbo+Cleaner+&+Power+Restorer+750ml+(Diesel)&rlz=1C1CHBF_enUS852US852&oq=Revive+Turbo+Cleaner+Starter+Kit+Turbo+Cleaner+&+Power+Restorer+750ml+(Diesel)&aqs=chrome..69i57.1170j0j8&sourceid=chrome&ie=UTF-8
 

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Discussion Starter #10 (Edited)
The odd thing is, watching the boost gauge it seems to operate normally. It jumps to about 20-25 psi when pulling the 5th wheel up an on ramp or similar, and runs between 5-10 when cruising with the trailer behind. Slightly less when not towing. I can get it to 22 psi on hard take offs empty.

When in tow mode and tune set to tow heavy, the exhaust brake slows the truck down just fine, towing or not. I am tending to think it might just be the position sensor, but do not want to throw money at it without proper testing.

I found this site, seems helpful but not conclusive as far as the sensor is concerned.
http://www.duramaxhub.com/service/6.6l-duramax-vane-position-sensor.html

A bit more so with the solenoid though. This is for it.
http://www.duramaxhub.com/service/6.6l-duramax-turbo-vgt-solenoid.html
 

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Discussion Starter #11
Sorry, the links got messed up. You might need to refresh the page to see them right, ai edited a couple times to fix them.
 
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