**ATS TCM Upgrade for GM 6.6L Duramax**

 

This upgrade replaces the A40 or A50 Transmission Control Module (TCM) in 2011-early 2015 GM 6.6L Duramax trucks with the T87A module. The A40 and A50 TCM, which controls the Allison 6-speed automatic transmission, is the weak link of the Allison transmission.

 

This is due to delicate, thin wires inside the TCM that short-circuit over time. In 2022, Allison issued a letter (SIL 15-1K2K-22) announcing the discontinuation of support for the A50 and A40.

 

This left over 10,000 Duramax owners without a solution. Therefore, we developed a solution utilizing our Translator technology from the ATS Allison Conversion to enable these trucks to resume operation, shifting and holding power more effectively.

 

The A50 and A40 TCM have been used in all GM Duramax/Allison Diesel Trucks produced from 2006 to 2017. ATS is pleased to introduce the new GM Allison T87A upgraded TCM module, which includes our Translator module with built-in Co-Pilot transmission functions.

 

**Features:**

 

* Compatible with both stock and modified trucks.

* Controls and increases line pressure.

* Direct replacement, requiring no permanent modifications. Plug-and-play OEM quality harness and module.

* Found in the current 2023 Duramax, the T87a TCM features a faster processor than the A50, resulting in improved shift quality, faster shifting, and enhanced drivability.

* Direct replacement for AC Delco: TCM 24256861, 25978353, 15117030

 

**Includes:**

 

* New T87a TCM, unlocked and pre-calibrated by ATS to optimize Allison transmission performance.

* New Translator module with enhanced Co-Pilot transmission pressure functions, enabling the factory Allison transmission to handle higher power levels and improved durability.

* Mounting bracket

* Wiring harness