What is the Anti-Lock Fuses Or Relay all about?

Modern braking systems have advanced considerably from what they were even a few short years ago. Today’s anti-lock brakes offer better stopping ability and safety during hard stops and on slick surfaces (although they don’t provide appreciably better stopping performance during good driving conditions). And while you might think these systems are largely hydraulic in nature, they’re actually more electronic. They require a number of electronic components in order to operate, and they need fuses and at least one relay. There are two primary fuses involved with the operation of a standard ABS system, although this varies significantly from one vehicle to the next and the exact number and configuration will depend on the ABS system manufacturer (not the automaker). One fuse allows power to flow into the system when the key is turned to on, activating the relay and closing it. Once the relay closes its contacts, the second fuse allows power to flow into the rest of the ABS system. If either fuse or the relay is blown, the system will not operate.

Keep in mind:

• Fuses are the weakest spot on a circuit as a safeguard.
• While relays fail much less frequently than fuses, they do fail from time to time.
• Failure of either fuse will result in the ABS system not operating, and the ABS light on the dash illuminating.

How it's done:

• The Anti-lock fuse or relay is verified that it needs to be replaced. The battery is disconnected.
• The defective Anti-lock fuse or relay is removed from its mounting connection and connection checked.
• The new Anti-lock fuse or relay is installed into the connector. The battery is reconnected.
• The Anti-lock fuse or relay is tested for operation with a scanner and all codes diagnosed and cleared.
• The vehicle is tested for proper operation of the Anti-lock system and the brakes.

Our recommendation:

In order to operate, your ABS system needs electricity. This is controlled by the anti-lock fuses and relay. The first fuse (a 10 amp fuse) must be good in order for electricity to flow to the relay, and the relay must function to provide power to the second fuse (a 30 amp fuse). This fuse must be good as well in order for power to flow into the entire ABS system. If you notice the ABS light on in your dash, have it diagnosed and replaced by one of our expert mechanics immediately.

What common symptoms indicate you may need to replace the Anti-Lock Fuses or Relay?

• ABS light on in dash
• ABS pump won’t work
• ABS system does not engage

How important is this service?

Anti-lock brake operation plays an important role in avoiding accidents and is essential to the safe operation of your vehicle. For most drivers, the only indication that there is something wrong with the anti-lock braking system will be the ABS light in the dash. Since most drivers rarely require the use of the ABS system itself, waiting to see if the system works properly is not safe. If the ABS light is illuminated in the dash, have one of our expert mechanics do an inspection immediately and replace any faulty fuses or relay.