--- title: "Allison TCM Repair: The Solution Is Finally Here" description: Is Allison TCM repair in your near or immediate future? If you use your 2009 to 2015 GM HD truck as intended, then the unfortunate answer is YES! image: https://blog.upfix.com/hubfs/Imported_Blog_Media/Allison-TCM-A50-T14-Repair-Service-1.jpg --- - [Help](https://www.upfix.com/help-center/) - [Track](https://www.upfix.com/order-tracking/) - [How It Works](https://www.upfix.com/how-it-works/) - [Contact](https://www.upfix.com/contact-us/) - [Shipping Address](https://www.upfix.com/how-it-works/shipping-instructions/) [![](https://blog.upfix.com/hubfs/UpFix%20logo.png)](https://www.upfix.com/) [![](https://blog.upfix.com/hubfs/web.png)upfix.com](https://www.upfix.com/) [![](https://blog.upfix.com/hubfs/phone.png)888-979-9343](tel:888-979-9343) - - - [tcm-repair-service](https://blog.upfix.com/tag/tcm-repair-service) # Allison TCM Repair: The Solution Is Finally Here [![Brian Medford](https://blog.upfix.com/hs-fs/hubfs/BrianM-1.png?width=50&height=50&name=BrianM-1.png)](https://blog.upfix.com/author/brian-medford) [Brian Medford](https://blog.upfix.com/author/brian-medford) June 27 2023 Last updated: March 4 2025 ![](https://blog.upfix.com/hubfs/Imported_Blog_Media/Allison-TCM-A50-T14-Repair-Service-1.jpg) Is Allison TCM repair in your near or immediate future?  If you are one of the thousands of 2009 to 2015 GM truck owners who use their vehicles as intended, then the unfortunate answer is YES! Maybe your luck has already run out and your Allison transmission is acting up or even worse, parked and out of service. Thousands of truck owners are already complaining that they cannot get replacement A50 T14 transmission control modules. The affected TCMs seem to be on indefinite backorder. People are devastated by the thought of not being able to drive their trucks. Getting your vehicle back on the road, and keeping it that way, is important. Here's what you need to know about [Allison Transmission Control Module](https://www.upfix.com/product-category/repair-return/tcm-repair/) failure and the [UpFix](https://www.upfix.com/) repair solution.   [![Electronics tech working on an Allison TCM.](https://blog.upfix.com/hs-fs/hubfs/Imported_Blog_Media/Allison_TCM_Repair_Technician.jpg?width=1200&height=816&name=Allison_TCM_Repair_Technician.jpg)](https://www.upfix.com/product-category/repair-return/tcm-repair/)*As the Allison A50 T14 TCM features microprocessors, the repair and software update process involves serious training, precision equipment, and many hours of labor.* ## Allison TCM Failure Symptoms The most notable symptom of a failing Allison A50 T14 TCM is hard shifting. This can cause havoc on your transmission's internal components and even your driveshaft U-joints. You may also end up in limp home mode” where your transmission sticks itself in third gear. At this point, the transmission has typically lost communication with the transmission control module. Don't expect the problem to fix itself. Think you can just keep driving? That's a bad idea. You're inviting further damage to internal transmission components from increased wear and tear -- likely increasing your repair bill by thousands of dollars.  A disabled truck on the side of the road can mean a big towing bill and lost productivity. Even if your TCM is not yet showing symptoms, it makes sense to schedule an Allison TCM repair during your next maintenance service. If you drive an 09-15 GM HD truck, don't wait until symptoms appear. ## Allison DTC Codes Here are common DTC diagnostic trouble codes associated with Allison A50 T14 TCM failure: - U0101, U0100 - Lost communication with TCM P0700 - Faulty Transmission Computer Module - P0827 - Up and Down Shift Circuit Low - P2669 - Computer Circuit Issue [![Allison A50 T14 TCM ](https://blog.upfix.com/hs-fs/hubfs/Imported_Blog_Media/Allison-A50-T14-TCM-Exterior3.jpg?width=1200&height=701&name=Allison-A50-T14-TCM-Exterior3.jpg)](https://www.upfix.com/product-category/repair-return/tcm-repair/)*Here's what your Allison A50 T14 TCM looks like. It's actually a great design, aside from the conformal coating intended to "protect" the electronics.  The issue is NOT unique to GM. Other applications including Freightliner CPC4 modules are experiencing similar conformal coating problems.* ## Allison TCM Problems: What Goes Wrong After many tedious post-mortem inspections of failed Allison TCMs, UpFix has found a design defect that causes internal failure. Heat and vibration take their toll on the circuit board conformal coating, which ironically is intended to protect it. This happens very slowly over time. Once the conformal coating starts to fail, the main microprocessor and a few other key components start to separate from the printed circuit board. TCM failures started occurring a few years after the affected trucks were put in service. Adding to the problem has been a wide-ranging long-term backorder of replacement TCMs, which is affecting or sidelining scores of trucks. For more detail, you can check out our troubleshooting guide **[HERE](https://forum.upfix.com/tcm/chevy-gmc-allison-tcm-gm-duramax-troubleshooting/)**  ## The Fix: UpFix To The Rescue Chevrolet or GMC, people LOVE their GM HD pickups. It's a shame to see trucks being disabled by a thin, faulty coating. Fortunately, the solution is here and it's crystal clear. Send your TCM to UpFix for repair. You'll find that your TCM unit is easy to access and remove with basic hand tools. Located on the core support to the left of the fan shroud, there's no need to crawl under the truck or raise the vehicle off the ground. Once the TCM is removed, your truck will be out of service for a few days. That's the only real downside, though. Once the unit is out, be sure to package it carefully to avoid any physical damage and ship it to UpFix for repair. This is NOT an exchange service. UpFix repairs your exact unit and sends it right back to you. Since it's YOUR part, you know it will be plug-N-play. Of the hundreds of types of electronics that UpFix repairs, the Allison A50 T14 TCM is perhaps the most complex and challenging. UpFix spent months developing and testing the repair process. Furthermore, a significant investment in new equipment was made. Unfortunately, a DIY enthusiast could not perform this repair at home. For example, there are more than 300 solder points just for the main microprocessor with more than 500 total. The failure points are rarely even visible to the naked eye but UpFix techs state that they can sometimes push on the various loose parts and feel them move. It's the larger components that are susceptible to separation from the PCB due to heat, vibration, and time. There is also a very specific procedure for cutting open the sealed case. UPfix no longer removes the entire case as seen in the photo below. They only remove sections of the case as needed. [![Allison A50 T14 TCM that has had its entire cover removed](https://blog.upfix.com/hs-fs/hubfs/Imported_Blog_Media/Allison_A50-T14_TCM_with_Cover_Removed.jpg?width=1200&height=902&name=Allison_A50-T14_TCM_with_Cover_Removed.jpg)](https://www.upfix.com/product-category/repair-return/tcm-repair/)*Here is what the inside of your A50 T14 TCM looks like before it is repaired.  The shiny conformal coating can fail due to heat and vibration. As a result, key components can separate from the PCB. * Before the repair begins, UpFix removes the conformal coating from key areas to prevent future problems.  A key part of the repair solution, UpFix replaces the main microprocessor along with numerous other key components. Improved thermal paste is used to keep future heat issues at bay. The unit is reprogrammed to the latest firmware specific to your vehicle.  You are required to supply a VIN number at the time of repair. Connectors are inspected and repaired if damaged. The entire unit is cleaned, inspected, and sealed. Note that your repaired unit will show signs of having been cut open and resealed. Once the hardware repairs are complete, UpFix uses sophisticated software to verify that each Allison TCM is working perfectly before being shipped. It's ready to install -- straight from the box. No local programming or VIN encoding is needed. It's a true plug-and-play solution. ## Affected Vehicles: Allison 3000 TCM A50 T14 TCM  At this time, UpFix provides repair services for Allison A50/T14 fourth-generation TCMs only. Allison TCM failures have been documented among these popular GM trucks: - 2009-2015 Chevrolet/GMC 2500/3500 "HD" Pickup Trucks - Chevrolet Kodiak, GMC Topkick C4500-C6500 - Some 2007-2008 and 2009 (You can send your 07-08 TCM to UpFix and have them determine if it is an A40 or an A50.) Typically these affected Allison TCMs are found behind Duramax diesel engines with engine RPO codes LBZ, LMM, LML, LLY, and LGH. A repair solution for 2001-2005 trucks equipped with Allison 1000 transmissions is in the works and nearing completion at this time. Unfortunately, older 2006-2008 A40 TCM units disintegrate during disassembly due to the use of a super-soft gel-like substance that was originally intended to protect the unit. The latest fifth-generation TCMs already are in use with no notable failures, thus far.   ![A GMC 2500HD with an Allison 3000 Transmission](https://blog.upfix.com/hs-fs/hubfs/Imported_Blog_Media/2014-gmc-sierra-2500hd-with-Allison-TCM.jpg?width=1200&height=800&name=2014-gmc-sierra-2500hd-with-Allison-TCM.jpg)*By the time GMT900 platform trucks started rolling off of assembly lines Duramax/Allison trucks were celebrated for their awesome towing capability. You could literally pull a house with one of these trucks. A50 T14 TCM use would extend into 2015 K2-platform trucks. UpFix prides itself on helping to keep desirable vehicles in service.* ## Allison TCM Repair Service: How To Order  Just remove your TCM from your truck. Do NOT attempt to remove the cover from the TCM as it can cause major damage to internal components.  Pack the unit carefully then use one of the links below to visit our [website](https://www.upfix.com/). Find your year/model and follow the instructions to reserve your [TCM repair service](https://www.upfix.com/product-category/repair-return/tcm-repair/). Chevrolet applications: [https://www.upfix.com/product-category/repair-return/tcm-repair/?make=CHEVROLET](https://www.upfix.com/product-category/repair-return/tcm-repair/?make=CHEVROLET) GMC applications: [https://www.upfix.com/product-category/repair-return/tcm-repair/?make=GMC](https://www.upfix.com/product-category/repair-return/tcm-repair/?make=GMC) During checkout, UpFix provides you with a helpful Drop-N-Go shipping label to save you from having to stand in line at a shipping store. You just tape the label to your sealed package and drop it off at FedEx or UPS drop-off locations in your town such as Walgreens, Office Max, Dollar General UPS store, etc. Learn more about drop-off locations here: Fed Ex: [https://www.fedex.com/en-us/shipping/drop-off-package.html](https://www.fedex.com/en-us/shipping/drop-off-package.html) UPS:[https://www.ups.com/dropoff](https://www.ups.com/dropoff)(Tip: You can hand your labeled package to any UPS driver) ![Guy carrying package into FedEx drop-off location](https://blog.upfix.com/hs-fs/hubfs/Imported_Blog_Media/UpFix-DropNGo-Shipping-Label-1.png?width=1200&height=675&name=UpFix-DropNGo-Shipping-Label-1.png)*These days, shipping a package could not be easier. Most towns have a dozen shipping locations including supermarkets, pharmacies, and actual shipping stores. UpFix makes the shipping process even easier by providing you with a pre-printed Drop-N-Go label, so you don't need to wait in line.* Previous Post ###### [FRM3 Footwell Module Repair for BMW and Mini](https://blog.upfix.com/frm3-footwell-module-repair-bmw-mini) Next Post ###### [Classic Toyota Prius Buyers Guide | Check These Parts](https://blog.upfix.com/classic-toyota-prius-buyers-guide) ### Similar Blog Posts #### [Speedometer Instrument Cluster Install/Remove Instructions](https://blog.upfix.com/speedometer-instrument-cluster-install-remove-instructions) [![](https://blog.upfix.com/hs-fs/hubfs/Imported_Blog_Media/july-2022-mazda-transmission-control-module-tcm-removal-guide-graphic-upfix-blog-1.png?width=352&name=july-2022-mazda-transmission-control-module-tcm-removal-guide-graphic-upfix-blog-1.png)](https://blog.upfix.com/tcm-removal-instruction-guide-mazda-transmission-control-module) #### [TCM Removal - Mazda Instruction Guide | Free TCM Removal Tutorial](https://blog.upfix.com/tcm-removal-instruction-guide-mazda-transmission-control-module) [![](https://blog.upfix.com/hs-fs/hubfs/Imported_Blog_Media/july-15-2022-tcm-exchange-program-explained-graphic-upfix-blog-1.png?width=352&name=july-15-2022-tcm-exchange-program-explained-graphic-upfix-blog-1.png)](https://blog.upfix.com/mazda-3-tcm-exchange-service-transmission-control-module) #### [Mazda 3 TCM Exchange Service | Moneyback Guaranteed](https://blog.upfix.com/mazda-3-tcm-exchange-service-transmission-control-module) ### ADDRESS UpFix 4991 BU Bowman Dr Buford, GA 30518 **International Shipping Available:** We ship to USA and Canada ### ABOUT Thank you so much for considering UpFix. 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