If you happen to own a 2009 through 2015 GM truck and have not experienced a Transmission Control Module (TCM) failure, congratulations. Of the many of these trucks still in service with an Allison transmission, many are susceptible to a TCM failure. This can lead to hard shifting, limp-home mode in third gear, and eventual vehicle immobilization.

Though TCM replacement might seem like an easy fix, ongoing and wide-ranging backorders plague the repair industry. Unfortunately, the backorder situation has many truck owners seeking a used TCM. Used TCMs are just another failure-prone unit. If you need to fix this issue, UpFix has an immediate time and money saving alternative; fix the truck’s existing TCM.

Whether you are a professional mechanic or do-it-yourself (DIY) truck owner, UpFix’s new Allison TCM repair service can get affected vehicles back in service and end the long and frustrating wait for an expensive, back-ordered replacement TCM. Since the repaired TCM is already matched to the vehicle, repairing an existing TCM eliminates the need for costly VIN encoding.

UpFix uses an improved thermal paste to better control any future heat issues and replaces key microprocessors updated with the latest firmware specific to your VIN.

Documented Allison TCM failures affect 2009-2015 Chevrolet/GMC 2500/3500 HD trucks, some 2008 and 2009 Chevrolet Kodiak and GMC Topkick C4500-C6500 vehicles. UpFix professionals conducted hours of post-mortem inspections and found the internal failure source.

Specifically, heat and vibration cause the TCM’s circuit board conformal coating to fail. This leads to transmission shifting issues, many of which started surfacing just a few years after the affected vehicles hit the road. The Allison TCM is used with Duramax diesel engines with engine RPO codes LBZ, LMM, LML, LLY, and LGH. The Allison A50/T14 fourth-generation TCMs have the highest failure rate.

“We start by removing the conformal coating from specific areas, a step to prevent future problems,” says Ernest Martynyuk, UpFix Auto electronics division lead. “We improve thermal paste to better control any future heat issues, we replace key microprocessors updated with the latest firmware specific to the vehicle and the vehicle’s VIN, then our techs inspect and repair all connectors, and finally, clean and inspect, and seal the unit.”

UpFix then uses sophisticated software to confirm the TCM functions perfectly. The finished repair is ready to install out of the box with no additional programming needed. To learn more, watch the video.

Once the non-functional Allison transmission TCM is removed and sent to UpFix for repair (customers can place an order and find shipping directions here), UpFix typically services and returns the renewed TCM in a few days. This is far better than waiting for open-ended new-stock inventory updates or even considering used parts that will likely suffer the same fate as the original TCM.

For the dedicated DIYer, Martynyuk cautioned, “Repairing a TCM is far beyond the skills of even the most advanced do-it-yourselfer. While many can remove and install the component, Allison TCM repairs require sophisticated capabilities and experience, as well as special repair, testing, and programming equipment. This is where we excel.”

“We specialize in fast, cost-effective, and professional repair services,” said Martynyuk. “A sidelined truck can really have a negative impact on its owner’s livelihood and lifestyle. Our goal is to help get these vehicles back on the road quickly whether individuals, auto and collision repair professionals, or commercial fleet managers. We’re on top of the latest techniques and technology to help ensure fast, reliable repairs.”

If the TCM in your Allison transmission is in need of some help, maybe you should check out to see if an UpFix repair is the right option for your GM truck.