Mustang GT 2008

My ABS, Brake light and Traction control light stays on. It will go of sometimes when it is raining outside. Sometimes it looks like Christmas lights going on and off. I have taken it to the Ford shop but they can’t figure it out.

If the primary brake warning light comes on, the ABS and Traction Control lights will automatically come on.

This is because the ABS and TC relies on the primary brake system to operate properly. And when it doesn’t these systems won’t function and turn their warning lights on to warn you of this.

So, once it’s found out what’s causing the primary brake warning light to come on, and that’s repaired so the light shuts off, the ABS and TC lights will also shut off.

Tester

I had an issue like this on my 04 buick rendevous and it turned out to be an abs sensor connector on one of my front hubs. I had replaced both of my front hubs which contain the sensors thinking the sensors were bad and the problem was still there. It wasn’t until I replaced the actual connector that fixed it. I actually replaced connectors on both sides and soldered them in good. I’ve read that you can test the resistance on the sensors, but starting with the connector might not be too bad of an idea because they’re only about $13 each online. Since you’ve already taken to the Ford dealer sounds like you’re in a throw parts at it kinda situation. So might as well start with the cheapest parts… Or at least check / clean them and make sure they have good connection.

Sounds like your ABS/Traction control module has gone bad. It’s one module that controls both the ABS and Traction control, if it goes bad then you’ll get warning lights for both systems

Unlikely in this case, but worth mentioning, on my Corolla I think the brake warning dash light comes on when the alternator is failing. I believe it is designed to do that, as a fail-safe. If the alternator warning light burns out, and the alternator fails, at least some dash light will come on alerting the driver that service is needed immediately.

The fluid level in the master cylinder is OK and the fluid level sensor is working correctly? This is where I would start looking first.