Volvo XC70, ABS light is on and it pops under the hood next to the serpentine belt, when I took it to a garage the said the sensors are working fine and turned the ABS light off and it stopped popping, i went over a brick layed road so it was very bumpy with a lot of vibration and the ABS light came back on and it’s started popping again under the hood, what could this be? The sensors are not loose as I have checked

 

the abs system has a controller board with solder joints that tend to crack and that in turn controls the solenoids in the ABS valve body which pulsate to regulate the fluid pressure to the wheels. You can try unplugging the abs board to see if the popping stops. Do you feel anything in the brake pedal? You can google around for services that will rebuild your ABS controller ($250 or so).

 

I have noticed there is an air leak somewhere in my system or a knackered air pump, could this affect the abs into clicking from the hood? I haven’t checked the module yet and will need to do it when I have some more time but Thankyou for the reply, on normal roads the brakes seem all good it’s just when I’m on bumpy roads I get a hard pedal and feels like The brake pedal is scraping on the concrete, I know it isn’t it’s just the only way to describe it, I can’t avoid the bumpy road either as I live on it