What is the Automatic Shutdown Relay all about?

When you turn the key for your ignition to start, many different things happen. The fuel pump turns on, sending gas from the tank, through the lines, to the injectors. The battery sends voltage to the ignition system, which creates a spark, igniting fuel vapor and starting your engine. However, if the automatic shutdown relay (ASD) is not working, none of this will happen.

The automatic shutdown relay controls the power that is supplied to the ignition, the fuel pump, and the injectors, as well as other components. It is only activated for a few seconds during cranking, and is then turned off. Depending on the make and model in question, the automatic shutdown relay could be located under the hood, under the dash, or in another position.

As with any other electrical component, your automatic shutdown relay is subject to wear and tear, and frequent stopping and starting of the engine will exacerbate that wear. Eventually, it will fail and you’ll be left with a vehicle that doesn’t crank.

Keep in mind:

• The ASD relay is not inspected during normal maintenance, and will only be checked during diagnostics for problems with the vehicle not cranking.
• Many other problems can cause your engine not to crank, so professional diagnosis is necessary.
• ASD failure is relatively rare, but it does happen.

How it's done:

• The automatic shutdown relay is verified to see if it needs to be replaced
• The defective automatic shutdown relay is removed
• The new automatic shutdown relay is installed
• The automatic shutdown relay is tested for operation
• The vehicle is tested to ensure proper operation of the automatic shutdown relay

Our recommendation:

Your automatic shutdown relay provides power for some of the most important systems on your vehicle during ignition. If it fails, your engine will not crank, and it cannot be jumpstarted. If you are experiencing a no start condition, it may be the ASD relay, but it could be another problem. Seek immediate professional diagnosis and replacement by one of our expert mechanics.

What common symptoms indicate you may need to replace the Automatic Shutdown Relay?

• Engine will not start
• Check Engine light is on
• Engine starts but stalls and dies

How important is this service?

Without an operational automatic shutdown relay, your engine will not start, which means your vehicle is not able to move. However, there are many other problems that can create the same symptom, ranging from a dead battery to a damaged battery, or a damaged cable to a failed main relay. If your automatic shutdown relay has failed, you will have to replace it before your vehicle will operate again.