ATV Fuel pump not shutting off with the key turned off: A Comprehensive Guide

Owning an ATV may have exposed you to a confusing situation when turning off the engine seems more difficult than imagined. Thus, if you are also facing this problem, don’t worry; in this article, we discuss all the possible solutions.

When the ATV fuel pump doesn’t shut off with the key turned off, it may be due to, a poor wiring connection, a faulty fuel pump relay, a clogged fuel filter, or a diaphragm issue.

Therefore, These are the problems that can be easily resolved by following the tips and tricks we have compiled here. Stick with us till the end!

Causes Why the Fuel Pump Stays On When the Key is Turned Off – Take A Look Here!

1. Poor wiring connection:

Damaged or short-circuited wiring can disrupt the electrical flow and cause the fuel pump to stay active. 

Despite it, damaged wire terminals, loose connections, and pinched wires can disrupt the electric flow, which can cause components of the fuel pump to malfunction.

2. Faulty fuel pump relay:

The next cause that is notable is a malfunctioning fuel pump relay. It can cause the fuel pump to remain operational even after the key is turned off. 

The relay is responsible for controlling the power supply to the fuel pump, and when it fails, the fuel pump might continue running.

3. ECM issues In The ATV

The ECM (engine control module) is meant to turn off the power supply to the fuel pump after 3 seconds of the initial priming of the pump thus if the fuel pump has to prime continuously, it is not doing so.

Once the priming of the fuel pump is complete, the voltage to the fuel pump stops, but due to a defective ECM, the fuel pump relay is continually grounded. Consequently, even when the car is not moving, the gasoline pump continues to operate.

The signs of a defective ECM are burn marks and moisture strains.

4. Ignition switch problems Letting The ATV Fuel Pump To Turn On

The most common cause of ignition switch problem is probably a shorted ignition switch.

Basically, the ignition switch get malfunctioned due to internal wear or corrosion problems in the system.

On the other hand, CDI (Capacitor discharge ignition) wire may always be hot if there is an internal short in the switch, constantly telling the CDI to start the engine. However, The function of CDI is to receive a pulse signal from the stator.

Here are the Common Signs of a Bad Switch:

  1. Only very gently turning the key will cause the ATV to turn off.
  2. When the key is turned approximately 3/4 of a full turn, the ATV switches off.

5. Fuel pump diaphragm issue

The diaphragm is responsible for creating the necessary pressure to deliver fuel from the tank to the engine. 

When the diaphragm becomes damaged or worn out, it can cause the fuel pump to lose its ability to shut off properly, leading to the problem of the ATV fuel pump not shutting off with the key turned off.

6. Clogged fuel filter

The main purpose of the fuel filter is to keep pollutants and debris out of the fuel system and the engine. When the filter becomes clogged, it restricts fuel flow, which influences the functionality of the fuel pump.

The fuel tank may become clogged with dirt, corrosion, and other particles over time. 

Now, after discussing the problems of the ATV fuel pump in detail, it’s time to give the solution to your problem.

Troubleshooting the “ATV Fuel Pump Not Shutting Off With Key Turned Off” Issue

1. Make sure that wires are connected correctly

1. Make sure that wires are connected correctly
Source: thespruce

Start with your ignition switch and trace the ground wires to the kill switch, CDI, and ignition coil. 

Make sure that all connectors are securely connected to their grounding location and are in good contact with bare metal. If you see signs of corrosion, detach the cable and use some sandpaper to clean the connector and connecting point to ensure a strong connection. 

Also check that no pins in the connector plugs are loose, which could cause them to back out when you connect the plugs. You may check to see if each pin is properly inserted by gently pulling them from the back of the plug.

2. Make sure that the kill switch and ignition switch are functioning properly

The ignition switch, key cylinder, or killswitch will be your next best option if your wiring appears to be in decent condition.

If there is only a little hint of corrosion, it is good to clean the contact points and give every part a good electrical cleaner spray. To prevent additional corrosion of the internals, fill the unit with dielectric grease.

You can check the switch for continuity if you have access to a multimeter. Depending on the wiring layout of your ATV, you may receive a positive signal while the key is off, a negative reading when the key is off, or the opposite. 

If all fails, then you have to replace the whole switch assembly.

3. Make sure that ECU and CDI are not damaged

Now it is time to handle the CDI or ECU/ECM module once you are sure that the ignition wiring and switches are working properly. 

There are a few things you can do to solve this issue before spending your hard-earned money on a new item.

Firstly, make sure that water is not getting inside of it. 

To check for corrosion or signs of water damage, disconnect the connectors from the box. Verify that the seals are secure and undamaged. 

4. Check the fuel pump relay

Follow these steps to check and test the relay:

  • Step 1: Locate the relay – Refer to your ATV’s service manual to find the fuel pump relay’s location.
  • Step 2: Inspection – Visually inspect the relay for any signs of damage or overheating.
  • Step 3: Testing – Use a multimeter to test the relay’s functionality. Follow the manual’s instructions to perform the test accurately.

5. Check the fuel pump diaphragm

To check the diaphragm:

  • Step 1: Remove the fuel pump – Follow your ATV’s service manual to remove the fuel pump.
  • Step 2: Inspect the diaphragm – Check the diaphragm for any signs of damage or wear.
  • Step 3: Replace if necessary – If the diaphragm is damaged, replace it with a new one.

Frequently Asked Questions:

1. For what purpose does the beep sound test perform?

This test can be run to determine whether the fuel pump relay is having a separate problem from other potential problem locations like the ECM and wire harness.

2. How long should the fuel pump run with a key on?

When you turn on the ignition in a fuel-injected car, the fuel pump turns on for a couple of seconds.

3. How often should I inspect my ATV’s fuel system for potential issues?  

Regular maintenance is essential for optimal ATV performance. Consider inspecting the fuel system and other critical components at least once a year or as recommended in your ATV’s user manual.


To sum up, 

The most common causes of the ATV Fuel pump not shutting off with the key turned off are a clogged fuel filter, a damaged fuel diaphragm, a shortened ignition switch, and a damaged ECM module. 

But in this article, we also compiled every possible solution for a better driving experience. So, enjoy!