I have a 2001 Chrysler Town & Country 3.8L w/164,000 miles. The brake and ABS light come on simultaneously while driving down the road. There doesn’t seem to be a time frame or anything that I am doing that will make it come on consistently. I have had the front and back brakes replaced. I disconnected the battery overnight, because I was told that may make it go away.(it didn’t) The brakes work fine, I?m just worried every time the light comes on.(not to mention the people that ride with me)
Can we assume that you have checked the master cylinder and you have verified that it is full?
You likely have a wheel speed sensor problem. The ABS functions by comparing the speed of the wheels and activating when it detects one not staying consistant with the others, indicating that the wheel has locked up. If it intermittantly loses one of the signals it’ll trip a fault code. The sensors will consist of a rotating piece that rotates with the wheel and a staionary sensor that detects the speed with which an index in the rotating piece passes by. That signal goes to a computer that activates the ABS when needed.
Take it to the shop and instead of telling them what to change, tell them the symptoms and let them do the diagnosis.
There’s a problem with the primary brake system. If there were just a problem with the ABS, the ABS light would only come on, and not the primary brake warning light. However, if the primary brake warning light comes on, the ABS light will automatically come on. That’s because the ABS will not function if there’s a problem with the primary brake system.
Once you figure out why the primary brake warning light is coming on, and have it repaired so that it turns off, the ABS light will also turn off.