Finding Stoplight Switch Signal to Install Prodigy P2 Brake Controller # 90885 on 2010 Buick Enclave

Question:

When installing the P2 in a Buick 2010 Enclave where does the RED wire terminate? The directions indicate termination on the wire that is only HOT when the brake pedal is engaged. However none of the three wires white, brown and green are hot only when the pedal is engaged. One is hot all the time white and the other two are never hot. Thank you for time

asked by: David R

Expert Reply:

The procedure on the Traverse/Terrain/Enclave is a little different than usual. There are at least two ways to find the stoplight switch signal. You can check under the under-dash trim panel for the brake controller connector, as shown in the photo. If the connector is present, you can use a circuit tester like part # PTW2993 on the wires feeding the connector. One of the wires should go hot with the brake pedal. If the connector isn't present, the brake stoplight signal can be accessed at the BCM. As you are sitting in the driver's seat, the BCM (Body Control Module) is located under the dash above where your left knee would be. The module (think of it as a junction box) will have 7 different wire connectors that plug into it.

Look for the brown connector (all the connectors are different colors) that has multiple slots for wires to insert into. In wire position # 5, there will be a light blue wire that carries the brake stoplight signal. Use the quick connector to tap the red brake controller wire into this circuit, and you will be good to go. Be sure to use a circuit tester in order to confirm that the light blue wire only shows voltage when the brake pedal is pressed.

expert reply by: Mike L