ABS Anti-Lock Control Relay
The term “anti-lock control relay” is something of a misnomer. The relay doesn’t operate the controller – the controller operates the relay. The relay itself is responsible for operating the pump, which pressurizes brake fluid in the ABS system’s accumulator. If the relay fails, then the pump will not operate and the fluid pressure in the accumulator will not build. The end result is that the ABS system won’t work.
Essentially, the anti-lock control relay is used to energize the electric pump in some types of ABS systems. This will vary from one system to the next, and is dependent not on the car manufacturer so much as on the manufacturer of the ABS system.
Like other electrical components, the anti-lock control relay is subject to wear and tear. Over time, it’s possible that it will fail, although pump failure is more common than relay failure, and fuse failure is more common than both. In all instances, failure means that the ABS system will stop functioning and the ABS warning light will illuminate in the dash.
Keep in mind:
- All relays are subject to failure due to normal wear and tear.
- The anti-lock control relay is not inspected during any maintenance service, and will only be checked if there is a problem with the ABS system.
- Many other problems can mimic symptoms of anti-lock control relay failure, including pump failure and blown fuses.
What common symptoms indicate you may need to replace the Anti-Lock Control Relay?
- ABS light is on
- ABS pump does not operate
- ABS system does not operate