It sounds like one of the sensors mounted in your bumper is bad or you have something obstructing one of them, mud, snow, etc.
unplug them one at a time until the noise stops, that will be the defective one
You woundn't find this type of info in a haynes manual . You would need a factory manual . Or a year subscription to alldata ALLDATAdiy com Buy Your Subscription Today .
have a 2005 ford focus and a lifter is making noise already put 5 bottles of fuel treatment in fuel i also change my oil every 2500 miles pkus i add a bottle of engine honey .are we taljing about alot of money to fix lifter doesnt burn oil
