How to Bypass Asd Relay In 5 Easy Steps (No Mechanic Required!)

In my journey to uncover the secrets of car maintenance, I researched “How to Bypass ASD Relay,” a nifty trick for every car enthusiast. Discovering this has been like unlocking a hidden chamber of knowledge, shedding light on the intricate dance between power and control in vehicles. It’s not just … Read more

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Written by: Mohammad Sameer

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In my journey to uncover the secrets of car maintenance, I researched “How to Bypass ASD Relay,” a nifty trick for every car enthusiast.

Discovering this has been like unlocking a hidden chamber of knowledge, shedding light on the intricate dance between power and control in vehicles.

It’s not just about bypassing; it’s about understanding your car’s heartbeat. Each step felt like peeling an onion, revealing layers of complexity and simplicity intertwined.

I was fascinated by how a small component could significantly influence your car’s performance. This exploration led me to appreciate the genius behind automotive design, making me see cars not just as machines, but as living, breathing entities.

Join me as we dive into this intriguing aspect of car maintenance, where every discovery is a step towards mastery.

Key takeaway

  • Finding the­ auto-shutoff disable relay in your vehicle­ is easy. It sits in the power module­ area along with other relays.
  • Once­ located, install a switch to control it. This lets you toggle the­ function on and off. Remove the conne­ctor from the ASD relay – it has two thin wires and two thicke­r wires.
  • Get some wire­ about 10 cm long and strip 3/8 inch from each end.
  • Connect the­ thicker wires togethe­r with the new wire pie­ce. This bypasses the safe­ty cutoff.
  • Now check the fuel pump – it should run continuously without stopping. If so, congratulations on comple­ting the modification successfully!

What is an ASD Relay and Why Bypass it?

The ASD relay is responsible for disabling the fuel pump when the vehicle is off, making it impossible to start or steal the car. Legitimate reasons to bypass an ASD relay include testing components like the fuel pump and performing repairs.

Bypassing the ASD relay allows you to operate the fuel pump even when the car is off. This should never be done to steal a vehicle.

Take Safety Precautions Before Bypassing ASD Relay

Troubleshooting Common Problems After Bypassing the ASD Relay
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Bypassing security features like the ASD relay can be potentially dangerous. Make sure to take precautions.

  • Wear protective gear like gloves and eye protection.
  • Work in a well-ventilated area away from flammable items. Fuel vapours are highly flammable.
  • Put wheel chocks in place so the vehicle doesn’t move.
  • Disconnect the battery to avoid electrical shorts.

Your safety should be the number one priority when working around fuel systems.

Gather the Right Tools to Bypass the ASD Relay

You’ll need some basic tools and materials:

  • Protective gear
  • Wheel chocks
  • Ratchet and socket set
  • Pliers
  • Bypass relay
  • Electrical tape
  • Wire cutters/strippers
  • Multimeter

Having the right tools for the job will make bypassing the ASD relay much easier. Consult your vehicle repair manual for any specialized tools.

Locate the ASD Relay in Your Vehicle

The ASD relay location varies across makes and models:

  • Often under the hood near the battery.
  • Inside the cabin near the fuse box.
  • Mounted on the firewall in some vehicles.

Consult your owner’s manual to find the exact ASD relay location. Identifying it correctly is crucial for this job.

How To Bypass ASD Relay: Step by Step

Safety Precautions Before Bypassing the ASD Relay
image source:

How to Bypass the ASD Relay

Once you’ve positively identified the anti-theft relay, you can move ahead with bypassing it:

Step 1: Disconnect battery cables properly to avoid sparks

Unhook the negative battery cable first, then the positive cable. This isolates the electrical system and avoids sparks or shorts when removing the relay.

Step 2: Unplug and remove relay completely

Unplug the wiring harness from the relay sockets. Then gently remove the relay from the socket. In some cases, you may need to unscrew or unclip the relay from its mounting bracket.

Step 3: Insert bypass relay correctly

Plug the bypass relay into the empty ASD relay socket. Make sure the socket pins align correctly with the bypass relay. If the sockets don’t match, you may need an adapter.

Step 4: Connect bypass wires properly including fuel pump bypass

  • Use strippers to remove about 1/2 inch of insulation from the bypass relay wiring.
  • Splice or attach these bypass wire leads to the corresponding ASD relay wiring using wire nuts or crimp connectors.
  • The trigger wire that disables the fuel pump needs to be bypassed.
  • Wrap all connections thoroughly with electrical tape for insulation.

Step 5: Reconnect battery once wiring complete

Once all wiring connections are made, reconnect the vehicle’s battery. With the bypass installed, you’ll be able to operate the fuel pump even with the key off.

Step 6: Verify bypass operation with key on, engine off

Turn the key to the ON position but don’t start the engine. Use a test light or multimeter to check for power at the fuel pump connector. If there is power, the ASD relay bypass is working.

Step 7: Remove temporary bypass relay when done

The bypass relay is only intended for temporary use when testing and troubleshooting. Make sure to remove it and reinstall the original ASD relay once you’ve completed your work.

Following these steps carefully will allow you to safely bypass your ASD relay. Never leave the bypass installed as it poses a major security risk.

Troubleshooting Common ASD Relay Bypass Problems

Sometimes issues can come up when bypassing the ASD relay. Here are some potential problems and solutions:

Problem: The fuel pump still not getting power with the bypass installed.

  • Solution: Double-check check all electrical connections are secure. Pins may be bent or corroded in the relay socket – inspect closely. Verify you installed the bypass relay correctly.

Problem: Engine cranks but won’t start with ASD relay bypassed.

  • Solution: There could be an additional security feature still disabling fuel delivery. Check for additional relays, and immobilizer components that require troubleshooting.

Problem: The fuel pump runs continuously with the key off after installing the bypass.

  • Solution: The bypass wiring may be faulty. Remove it immediately and recheck the relay wiring diagrams. Never leave the bypass installed unattended.

Problem: Car alarm or security indicators activate with ASD relay bypassed.

  • Solution: The vehicle computer is detecting the missing relay or fault. You’ll need a diagnostic scanner to override the alarm in most cases. Consult a professional mechanic.

Problem: The bypass relay gets very hot during operation.

  • Solution: This indicates an overloaded circuit or incorrect wiring connection. Shut off everything and recheck the bypass wiring thoroughly.

Diagnosing bypass connection issues requires patience and care. Taking the time to troubleshoot will ensure you complete the ASD relay bypass properly without damaging components.

Benefits of Temporarily Bypassing the ASD Relay

There are a few key benefits to safely bypassing the ASD relay when needed:

Allows Fuel Pump Testing

Bypassing the relay activates the fuel pump, letting you diagnose pump issues and test pressure/volume. This is difficult to test with the anti-theft relay functioning normally.

Isolates Electrical Problems

If you suspect issues with fuel pump wiring or connectors, bypassing the relay isolates the problem area. Any sparks or shorts will be avoided with the relay removed.

Facilitates Repairs Requiring Fuel Pump Operation

Some automotive repairs like fuel filter replacements require running the fuel pump to bleed air out of the system. The ASD bypass allows this pump priming with the key off.

Provides Electrical Troubleshooting Access

Bypassing the relay gives easier access to the pump and relay connector pins for diagnostic testing with multimeters and test lights.

Keep in mind the bypass should only be temporary and removed after completing your testing. When installed by qualified technicians using proper precautions, the ASD relay bypass can be a useful diagnostic tool.

FAQs: How to Bypass Asd Relay

Is bypassing ASD relay illegal?

Yes, bypassing the ASD relay is technically illegal under EPA and state laws prohibiting tampering with emissions controls.

How can I disable ASD relay without voiding warranty?

Use a tuning method that is reversible to stock. Permanent hardware modifications will void powertrain warranties if discovered.

What are symptoms of a bad ASD relay?

A faulty ASD relay can cause stalling, rough idle, no start, traction control light, check engine light, and PCM codes.

Can a bad ASD relay cause no start?

Yes, a failed ASD relay can lead to a no crank or crank no start condition in many Ford vehicles as it is critical for proper operation.

How do I reset adaptive memory after bypassing ASD relay?

Disconnect the battery for 15 minutes after re-enabling ASD relay. This resets PCM adaptive values related to traction control and throttle to allow relearning.


Temporarily bypassing your anti-theft ASD relay can provide access to the fuel pump circuit for legitimate troubleshooting purposes. However, extreme caution should be exercised since you are disabling a major security feature.

The steps outlined in this guide demonstrate how to safely locate your ASD relay, install a temporary bypass, complete your vehicle repairs or testing, and remove the bypass once done.

Never leave an ASD relay bypass installed in an attempt to steal or drive the vehicle. Doing so presents major legal and safety risks. Only qualified mechanics should conduct this procedure using proper tools and precautions.

Hopefully, this detailed walkthrough gives you a better understanding of how and when an ASD relay bypass might be useful. Let me know if you have any other questions!

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About Mohammad Sameer

My name is Mohammad Sameer and I have over 3 years of hands-on experience repairing cars, motorcycles, and trucks. Ever since I operated on my first engine in 2018, I’ve been passionate about all things automotive. In 2021, I launched my blog “Motoring Mastery” to share my knowledge with car enthusiasts and DIY mechanics.