Strange brake light behavior 2011 Impala

[Elkins45]

I followed my wife driving her dad’s 2011 Impala today and the brake lights were malfunctioning. The stayed on for almost the entire trip. When she started moving after a stop they would go off for a few seconds but then come back on almost continuously. After braking they went off but came back on within 5-10 seconds. She wasn’t riding the pedal.

The car is a salvage title so heaven knows what else is screwed up with it. She said the cruise control didn’t work either and one intersection of those two systems is the brake light switch, so my assumption is just to replace it before messing with anything else. Right? I hate intermittent electrical problems, but at least this one seems repeatable.

 

[Nukeman7]

It is highly likely that the brake light switch is the culprit. Either the switch plunger is sticking (more likely) or the gap needs to be adjusted between the switch and the brake pedal arm. I'd visually inspect the gap and give the switch plunger a spritz of lube or WD-40 before replacing the switch.

 

[FowVay]

I think that car uses a brake pedal position sensor as opposed to a simple on/off switch. My dad used to have an Impala that the sensor went bad on and the brake lights would stay on all of the time. He noticed it one day when he pulled into the garage and shut the garage door and saw the brake lights on.

Another symptom would be the failure of the cruise control system.

Anyway, they're cheap... <15 bucks. P/N 25912943

 

[Nukeman7]

FowVay is 100% correct, the Impala uses a "sensor" that rotates instead of the typical plunger switch. As such, replacement is the answer since lubricating it won't be effective and it has no adjustment capability. Here is a YouTube video that shows how easy it is to replace. Ignore the narrator's heavy accent and fast forward to the 2 minute, 30 second mark to see the work being performed.

 

[repairman54]

Fretting corrosion in the BCM connectors was an issue in '08 to '12 Malibu's for erratic brake lights. They had a recall for that. May be a possibility also in an Impala if pedal sensor does not fix it. Most likely same components were used across the lines.
May have to perform a recalibration also.