I've heard that GM made updates to these turbos to correct this issue, the one in this PI would bolt right to your truck. Don't really know the difference between LBZ and LMM turbos? and I don't know if the updates were retro active to earlier models, But There are a bunch of gentlemen here with extensive blow dryer knowledge and If paying cash out of your pocket do more research and compile all info you can. IIRC some years of Ford use these turbos also.
2007 Chevrolet Silverado - 2WD | Sierra, Silverado VIN C/K Service Manual | Document ID: 2547779
--------------------------------------------------------------------------------
#PIP4857: Diesel Engine Turbocharger Performance DTC P2563 - (Nov 22, 2010)
Subject: Diesel Engine Turbocharger Performance DTC P2563
Models: 2007-2010 Chevrolet Express, Kodiak, Silverado
2007-2010 GMC Savana, Sierra, Topkick
Equipped with the 6.6 LMM Diesel Engine
--------------------------------------------------------------------------------
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
A dealer may encounter a customer concern of reduced power and DTC P2563. The concern described in this PI will occur more often on vehicles that are driven in high ambient temperatures and towing at (or near) the gross vehicle weight limit.
There has been an updated turbo released to address this condition.
Recommendation/Instructions:
It is imperative the P2563 diagnostic is completed. P2563 can set due to control solenoid or position sensor concerns. Also see the newest version of PIP4629 for diagnostic assistance. P2563 sets when the ECM detects the turbocharger actual and desired vane positions are not tracking. With the condition described in this PI, the turbo unison ring will stick in a high turbo boost request position. If duplicated (or a snapshot of concern is captured), the actual vane position may be noticed at approximately 70-80%, and the desired position will be approximately 20-30 %. This could occur during a deceleration, or during any other engine load changes that the ECM requests a lower vane position and/or a lower turbo boost pressure. Due to the vanes sticking in a high turbo boost position there may not be any loss of power noticed before the P2563 sets. The condition described in this PI may be hard to duplicate unless the vehicle is loaded.
1. Inspect the oil feed line to the turbo, a kinked or damaged line may induce the same type of condition.
2. Verify the customer has not used an aftermarket calibration per newest version of bulletin number 08-06-04-006.
3. If SI diagnostics have led to a sticking vane turbo with DTC P2563 set, replace the turbo. Use updated turbo part number 12639460 for repairs.
Note: Some dealers may notice that DTC P0108 has set along with P2563. Please do not replace the MAP sensor if P0108 has set along with DTC P2563 (setting as described in this PI). Diagnose and repair turbo concern and evaluate P0108.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.