Have you found that the integrated remote door control buttons in your 2007 Impala aren’t working with your new garage door opener? Many owners of 2007-2013 GM vehicles, including the Impala, have encountered this issue when upgrading to modern garage door and gate operators. The problem lies in the Car2U system installed in these vehicles, which is often incompatible with the latest Security+ 2.0 protocol used by many new openers. Let’s delve into why this happens and explore a solution to get your factory car buttons working with your new garage door.
Understanding Car2U and the Incompatibility Issue
General Motors vehicles, including the 2007 Impala, and some Ford models from 2007-2013 were equipped with the Car2U remote system, manufactured by Lear Corporation. These systems are identifiable by three yellow LED lights above the control buttons. The original solution for compatibility issues, as suggested by LiftMaster, involved a Car2U repeater from Lear. According to a LiftMaster compatibility notice:
Select 2007-2013 GM and Ford vehicles may have Car2U remote systems manufactured by Lear Corporation, identified by three yellow LED lights, one above each button. A Car2U repeater purchased from Lear is required for all vehicles. Contact Lear at www.learcar2u.com or at 1-866-572-2728.
Unfortunately, Lear Corporation, the manufacturer of Car2U, is no longer in business, and the Car2U repeater is no longer available for purchase. This renders the original recommendation ineffective unless you can find a used repeater.
The root of the problem is that older Car2U systems operate on different frequencies and protocols than modern garage door openers like the Chamberlain B4505T, which utilize Security+ 2.0. Even newer vehicles, like a 2016 Impala mentioned in the original article, may still use the older Car2U system, highlighting that Gen 8 Impalas were consistently built with this onboard technology. While bridges for older HomeLink systems exist, Car2U uses a distinct protocol, making those bridges incompatible.
The Wired Bridge Solution: Bridging the Protocol Gap
Faced with the unavailability of Car2U repeaters, a viable alternative involves using wired bridge devices marketed by LiftMaster. These bridges are designed to translate signals between different frequency bands. Specifically, the 412HM bridge, operating at 390MHz, has proven effective in receiving signals from Car2U systems. Initially, a 312HM (315MHz) might seem like a possibility, but it will not receive Car2U signals, as confirmed through testing.
However, simply receiving the signal is only half the battle. Modern garage door operators with Security+ 2.0 employ digital pulse code commands for their wall controls, unlike older systems that used simple contact closures. Therefore, the standard contact closure output from the 412HM bridge is insufficient to directly operate the new door operator.
To overcome this, the solution involves integrating a button-style wall control with analog-to-digital circuitry. These controls, such as the LiftMaster 883LMW, still use a physical button press resulting in a contact closure. Crucially, they internally convert this contact closure into the necessary digital command for the new door operator.
By connecting the contact closure output terminals of the 412HM bridge to the button circuit within the 883LMW wall control, you effectively simulate a button press. The 883LMW then translates this into the correct digital signal for the Security+ 2.0 garage door opener. The complete circuit configuration is visually represented in the diagram below:
Wiring diagram for connecting a Car2U wired bridge to a Security+ 2.0 garage door opener system. This diagram illustrates how to integrate the 412HM bridge and 883LMW wall control to enable Car2U compatibility with modern garage door openers.
For a more streamlined setup, the circuit board from the 883LMW wall control can be extracted and installed inside the 412HM bridge enclosure. This creates a single, integrated unit that neatly connects to your new garage door operator. This solution not only restores the functionality of your 2007 Impala’s built-in Car2U system but also allows you to use older remotes with the new Security+ 2.0 opener.
Step-by-Step Instructions
For those who prefer detailed guidance, comprehensive instructions on building this wired bridge solution are available in PDF format: Building a Lear Car2U Wired Bridge for Security+ 2.0 Garage Door Openers This guide provides a step-by-step walkthrough, eliminating the need for extensive research and trial-and-error.
Conclusion: Reclaiming Car2U Functionality
If you’ve upgraded to a Security+ 2.0 garage door opener and want to retain the convenience of your 2007 Impala’s built-in Car2U remote system, this wired bridge solution offers a practical path forward. While it requires some hands-on effort, following the outlined steps and instructions will successfully bridge the compatibility gap. This approach not only solves the immediate problem but also provides a rewarding DIY project, especially for those who appreciate elegant and integrated solutions.
