What is the Anti-Lock Pressure Switch all about?

Modern anti-lock braking systems are highly reliable, and offer safer stopping in certain driving conditions. They’re also very complex systems that rely on a network of sensors, switches, and other components in order to operate. The ABS system actually spans most of your vehicle, although much of it is found under the hood, centered on the master cylinder. In an anti-lock brake setup, pressurized fluid must be stored in order to provide a power assist to brakes during ABS pulsing. The fluid is pumped into and held in the accumulator, and the anti-lock pressure switch is responsible for turning the pump on and off.

Essentially, the anti-lock pressure switch is an on/off switch for the ABS pump. When the fluid in the accumulator is low, the switch turns on the pump. The pump runs until the accumulator is full, and then the switch turns it off. However, over time, the switch can wear and failure is a possibility. When this happens, the pump will not operate, or it could burn itself out in some situations.

Keep in mind:

• The anti-lock pressure switch is not inspected during routine maintenance, and will only be checked if there’s an ABS problem.
• If the anti-lock pressure switch fails, the ABS system will not operate.
• A failed pressure switch will turn on the ABS light on your dash, and set a brake system code in the computer.

How it's done:

• The anti-lock pressure switch is verified to see if it needs to be replaced
• The defective anti-lock pressure switch is removed
• The new anti-lock pressure switch is installed
• The anti-lock pressure switch is tested for operation
• The vehicle is tested to ensure proper operation of the anti-lock pressure switch

Our recommendation:

The anti-lock pressure switch is a small but important component for the entire ABS system. If it fails, the system won’t work, although you’ll still have normal braking capabilities but not the ABS. Have any brake system problem diagnosed by one of our expert mechanics as many different problems can set a code in the computer and turn on the ABS light on the dash.

What common symptoms indicate you may need to replace the Anti-Lock Pressure Switch?

• ABS light is on in dash with brake system code set in computer
• ABS system does not work
• ABS pump will not stop running

How important is this service?

Without a functional anti-lock pressure switch, the ABS pump cannot operate properly, and the system as a whole will shut down. Damage to the pump is possible in some instances. If you have an ABS light on in your dash or have noticed any other abnormal operation, have it diagnosed and replaced by one of our expert mechanics immediately.