SEMA 2025: Haltech’s New Ti4L And Ti6L Controls GM’s Electronic Transmissions

When Haltech’s Nexus Rebel LS plug-and-play kit came out, it was an easy, powerful option for anyone running a Gen III or Gen IV engine, with one caveat: You had to be running a manual transmission, or a non-electronically-controlled automatic. That last sentence is in the past tense, intentionally, as now, with the release of its new Nexus Ti4l and Ti6L Transmission Interface Kits here at the 2025 SEMA Show, Haltech is able to control GM’s 4L-series of transmissions, along with 6L80 and 6L90 transmissions.

The Ti4L and Ti6L are not standalone controllers, but rather an interface kit allowing a Nexus ECU or VCU to control one of GM’s supported electronic four- or six-speed transmissions. The kit includes a fully terminated plug-and-play transmission harness that seamlessly integrates with the Nexus Rebel LS ECU harness. The existing Rebel LS software has control options available via the setup wizard through the Haltech NSP software or the Haltech Connect app. Both of those software solutions also offer easy TCM OS update support.

The kits come with the controller, harness, a 500psi line pressure sensor, and the required mounting hardware, making this an incredibly simple installation. As previously mentioned, both the Ti4L and Ti6L are plug-and-play with the Rebel LS system, but if you are using a different one of Haltech’s Nexus ECUs or VCUs, a little extra wiring is involved. It’s nothing crazy, just the need to manually terminate the ECU’s harness to connect to the DTM-8 transmission breakout connector on the harness with the included connector and pins.

The Nexus line of ECUs and VCUs have taken their next step of advancement into being the ultimate LS control system, as all of the most popular electronic four- and six-speed transmissions are now able to be controlled effortlessly.