VEHICLE TECHNOLOGY Module 10 Topic 4

VEHICLE SUSPENSION Helps to smooth out weight transfers Helps keep all four wheels on the ground Helps keep the vehicle level

ABS AND TRACTION CONTROL SYSTEMS Anti-lock brake systems are designed to allow steering and simultaneous braking without losing vehicle balance. ▪ Traction control systems are designed to activate brake sensors, which do not allow the wheels to spin. The device allows acceleration input without loss of vehicle balance. Suspension control systems adjust vehicle balance at struts or shock absorbers through adjustment of fluid or air pressure when too much weight is suddenly transferred to a given shock or strut Electronic Stability Program (ESP) compares where a driver is steering the vehicle with where the vehicle is actually going. When ESP senses a disparity between the two, it selectively applies any one of the vehicle’s brakes to reduce the discrepancy and help the driver retain control and stability.

ANTI-LOCK BRAKING SYSTEM (ABS) ABS allows maximum stopping force without locking up the brakes (skidding) If standard brakes are applied too hard, the wheels "lock" or skid, and you lose steering control.

If steering control is lost, the vehicle skids in a straight line wherever it is going ABS is an anti-lock/anti-skid brake system that allows the driver to steer during hard braking Anti-Lock Braking System (cont)

The ABS warning will come on when there is a problem with either the ABS brake system, normal brake system, or the brake fluid is low in the master cylinder or the ABS brake system To find out if a vehicle is equipped with ABS, turn on the ignition and check the instrument panel for the ABS indicator light Anti-Lock Braking System (cont.)

2 TYPES OF ABS 4-wheel ABS: ▪Generally found on passenger cars; ▪Designed to maintain steering ability in emergency braking situations Rear-wheel ABS: ▪Found exclusively on light trucks; ▪Designed to prevent the vehicle from skidding laterally

In a parking lot, go mph and execute an emergency stop to engage ABS Keep your foot firmly on the brake even when you feel the brake vibrate and/or hear noise This computerized pumping action can pump the brakes up to 15 times per second Practice Activating ABS

There are fewer fatal crashes for cars equipped with ABS False, some drivers panic and/or release the brake when it pulses Don’t use ABS brakes on a slippery surface False, ABS shortens stopping distance and improves control on a slippery roads Myths about ABS

ABS DO’S Do maintain firm & continuous pressure on the brake while steering to enable 4-wheel ABS to work properly Do allow enough distance to stop: ▪Follow 4 or more seconds behind vehicles if conditions are good; ▪Follow 6 or more seconds if conditions are adverse

ABS DO’S Do practice with ABS in empty parking lots to become familiar with the pedal pulsations Do consult the owner’s manual for additional instructions

ABS DON’TS Don’t drive an ABS-equipped vehicle more aggressively Don’t pump the brakes: ▪Pumping the brake turns the ABS system on & off Don’t be alarmed by the noises & pedal pulsations Don’t forget to steer

ESP In Case of Oversteering When ESP detects oversteer, it applies the outside front brake. In Case of Understeering When ESP detects understeer, it applies the inside rear brake to help the vehicle rotate faster.