My HCU randomly comes on (94 Mark 8). I hear a rumble and feels like the car slows just a little bit. I disconnected the sensors and it is still happening. I'm guessing it's the HCU but I don't know how to disable it to see if the problem goes away. Does anyone know how this can be done or have any troubleshooting advice? The trac assist button lights up off all the time and will not switch to on. Thanks for you help.
Tim
Tim