2007 Pontiac G6 Cruise/Brakelights

[Dave S]

About a month ago, I passed a G6 with the brakelights on. I just thought the driver had his foot on the brake pedal just enough to cause them to be on.

Last week my wife came home complaining that her cruise doesn't work. The following day I noticed her brake lights were on. I know the 2 are related (brakes applied turns off the cruise).

What could be causing this? There's now been 2 cars of the same make in the past 4 weeks that I've seen do this.

Thanks for any help.

[Jeremy airjer W]

I would bet the brake pedal position sensor (no longer a switch as it provides a variable input signal to the BCM which then grounds the brake light relay and or alows the cruise to engage disengage) has gone bad. Its the only thing I can see that the two have in common besides the BCM.

The should be 5 volts at the grey wire and variable voltage depending on the position of the pedal on the yellow wire. There should be less than 1 volt with no brake applied.

There is a recalibration procedure that requires a scan tool ($$$$$$). This needs to be done before the switch is replaced in order to eliminate a calibration issue or after the switch is replaced in order to calibrate the new one.

As far as I know a GM tech2 scan tool is the only one that can do this that I am aware of right now. Possibly the higher end snap on/otc may be able to as well.