How to Bypass ASD Relay: All You Need to Know

The Automatic Shutdown Relay (ASD) is widely used in modern cars and is essential to the entire engine management system. However, the ASD can become faulty over time, or you may have a bad ASD relay, and it may need to be bypassed for the vehicle to function optimally. But how do you bypass ASD relay?

If you wish to bypass your ASD relay, you need to have a sound understanding of what it is and how it works first. As a result, this article covers everything you need to know about bypassing the ASD relay.

This article discusses what the Automatic Shutdown relay is and how it functions. We then look at when it is necessary to bypass the ASD relay. Finally, we look at the entire process and step-by-step methods used for bypassing the ASD relay.

What Is The Asd Relay?

The Automatic Shutdown Relay or ASD relay is a basic relay for efficient use of the fuel injectors and ignition systems in modern-day cars. The ASD relay supplies switched power to the car’s fuel injectors, ignition coils oxygen sensor heater relay, and other electrical components.

What Is The Asd Relay

The ASD acts as a safety feature and is controlled by your vehicle’s computer system and logic module. Upon ignition switch in the Automatic Shutdown relay will supply power to the various other components mentioned above. The ASD relay is a crucial component to ensure your car engine starts and is working properly.

However, when the ignition is off the ASD relay shuts off power to the ignition coils, fuel pump relay circuits, oxygen sensor heater relay, and other relays. Doing so will ensure that your car does not use power needlessly and prevent live currents from flowing through your relay terminals when the engine ignition system is in the off position.

If you wish to bypass the ASD relay you need to know where it fits in your car and how it works.

How Does the ASD Relay Work?

How the ASD relay functions is a detailed process. However, knowledge of the ASD circuit is crucial if you want to bypass the relay. As a result, we summarized this process below.

Terminal 30 connects both the Automatic Shutdown relay and the fuel pump to your car’s battery voltage. The powertrain control module acts as a ground circuit for the ASD relay from the side of the relay coil. Terminal 86 will provide power to the ASD relay through the relay coil side.

How Does the ASD Relay Work

When the car engine is switched to the off position the powertrain control module will stop transmitting power to both the ASD relay and fuel pumps and force an automatic shutdown. However, when the ignition is set to the on position the power control module will connect terminals 3o and 87 and supply power through terminal 87.

The above paragraphs paint a picture of the circuit diagram related to the ASD relay. This information is essential to understanding how the ASD relay can be bypassed. It also explains why a bad ASD relay may prevent smooth operation and cause issues with your car.

How To Spot A Faulty Automatic Shutdown Relay

Like most electrical components the ASD relay will likely begin to fail due to age or electrical failures. The ASD relay can be responsible for a myriad of car troubles. Unfortunately, spotting the ASD relay as the reason for your car failure is not always blatantly obvious and you need to know what you’re looking for. We’ve listed the most common signs that your ASD relay may be at fault.

How To Spot A Faulty Automatic Shutdown Relay

Engine Fails to Start

If there is an issue with any part of your circuit your ASD may prevent your engine from starting and remaining in the off position. While the issue may be another relay on your circuit it is actually the ASD relay that prevents the fuel pump relay and other integral relays from stating up.

While the initial problem should be addressed the engine will still likely be able to start and run if the ASD did not kick in. As a result, it may be beneficial to bypass the ASD relay terminals in this case.

Stuttered and Stalling the Engine

If your engine is stuttering upon ignition or stalls frequently, even during driving, your ASD relay may be at fault. A faulty automatic shutdown relay may improperly trigger a shutdown of power to vital engine systems. Additionally, it may take longer for your engine to start if you have a bad ASD relay.

An old ASD relay may be faulty and assume the ignition is off when you are trying to start the engine. This would prevent the fuel pump from firing as well as the fuel injectors. Likewise, you may be able to start your car but notice that while driving your car will stall. This issue can occur for the same reason as your ASD may assume the ignition is off and shut down power to vital engine systems.

Check Engine Light On

The check engine light warning is notorious for being vague as there are countless reasons for it being illuminated. However, the ASD relay is a common culprit. Your car’s logic module will pick up an error with the ASD and switch on the light.

Unfortunately, there is no sure way to tell it is the ASD relay without bypassing it or replacing it. Nonetheless, we would still recommend you take your car in for a full vehicle scan when the engine warning light appears.

Buzzing and Clicking Noise Coming From Circuit Relay

If you open your relay section in your car you may hear a buzzing noise or clicking noise coming from the ASD relay. If this is the case the ASD relay may have a faulty connection or may be shorting power coming from the car battery.

A faulty wire, terminal resistance, and other circuits may be causing your ASD to short circuit and cause interruptions in the power supply of your car. Replacing the ASD may resolve the issue but it should be done with care. A faulty ASD relay could create a live current with other contact modules and lead to electrocution. Bypassing the ASD relay may also resolve the issue temporarily.

Methods for Bypassing  ASD Relay

Luckily, it is possible to bypass ASD relays and is relatively simple. More so now that you understand how the ASD works and what it’s responsible for. Furthermore, there is more than one way to bypass the ASD so you can choose what works best for you. We break down each method and the tools you may need to get the job done.

Method 1: One Wire Method

How it Works

This method should only be used in an emergency as it is not a long-term solution and the wire may not hold. If the wire moves around it may cut power from the battery to the fuel pump and stall the engine. The wire will essentially act as the ASD relay by drawing power from the battery into the other systems. As long as the wire is connected it will feed power to the ignition coils and allow you to start the car. Note that even when the ignition is off the wire will still be feeding power to the other modules.

Tools Needed

As the name suggests, all you’ll need is a single jumper wire. We recommend a 16GA jumper wire but you could also make do with a 10GA jumper wire or even a paper clip can work if you’re in a tight spot or emergency.

A Step by Step Guide

  • Step 1: Open up the power module and locate the ASD relay.
  • Step 2: Remove the ASD relay and put it somewhere safe.
  • Step 3: Place one end of the wire into the 87 terminal and the other end into the 30 terminal. You will hear a clicking noise as the other relays and terminals activate.
  • Step 4: Start the car with the ignition key and see if it worked.

Method 2: Keeping the Relay Intact

How It Works

This method is more technical than the last one but it is a better long-term solution. Use this method if the nearest garage is miles away and you need to travel long distances. Essentially you’re going to cut 3 wires and ground them and splice them to the ignition. This will successfully bypass the ASD relay and does not run the risk of a wire fire.

Tools Needed

To successfully do this job you’ll need a number of tools at hand. In short, you’ll need heat shrink, dimple crimpers, a single ring terminal, and 3 non-insulated butt connectors. Cutting wires may seem daunting at first but if you have the technical know-how it’s easy.

A Step by Step Guide

  • Step 1: Make sure the car is off and the ignition key is out. Open the power module box and locate the ASD relay. Also, make sure to view the circuit diagram.
  • Step 2: Locate pin 85 at the base and cut it. Then and ground it to a clean ground.
  • Step 3: Locate and cut wire 86. Then splice wire 86 to the main ignition hot wire.
  • Step 4: With the relay in its original position, switch on the car and test. The really will ideally switch on and off with the ignition key.

Other Ways to Fix a Bad ASD Relay

While bypassing the ASD relay may be the best option if you have no others, it is not the most convenient. As a result here are a few other ways to fix a faulty ASD relay.

Fix a Bad ASD Relay

Get a Replacement

ASD relays are widespread throughout modern cars and as a result, they are widely available. It may even be possible to replace your ASD with the ASD of another car if that is an option for you. Replacing the ASD with a new one is the better option because it doesn’t require tampering with your car and handling wires and other electrical systems.


You should not try to bypass your ASD really if your car is still under a service plan. Instead, take your car in and get it checked. If your car is still relatively new and the ASD is failing it could indicate a larger issue.


The ASD relay is a useful and integral component of your car. However, age, degradation, or a multitude of other reasons can cause it to faulty. In such instances, bypassing the relay is an effective way to get your car starting.

In this article, we discussed what an ASD relay is and what it does. We also outlined some things to look out for to tell if you have a faulty ASD. Following this, we looked at 2 methods you can use to successfully bypass the relay. Finally, we provided some alternatives to bypassing the relay. Hopefully, this article helped you fix your ASD relay, or at the very least, gave you a better understanding of how it works.

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