Luvi Silverberg
November 15, 2022

How to Reset Cummins N14 ECM


The Cummins N14 engine is one of the most reliable and durable diesel engines available. It's so robust, in fact, that it can last for up to 500,000 miles without ever needing an overhaul. But even though these engines are incredibly tough, they still require regular maintenance just like any other machine. Maintaining a Cummins N14 ECM is especially important because the computer controls all the various components on your vehicle or machine - from generating power to controlling emissions levels - and therefore has an effect on every function it performs. If your engine isn't performing well or if something about its operation doesn't seem right (such as sudden loss of power), resetting the ECM might help solve this problem by resetting all its parameters back to factory default values so it can calibrate itself again properly

Shut down the engine.

  • Shut down the engine. This step is necessary for safety reasons and to avoid damage to your vehicle's electrical system. To shut it down, turn off the ignition and turn off all power sources to the engine. You can do this by turning off the fuel pump, disconnecting its battery connection or shutting off a circuit breaker within your home's fuse box.

  • Remove any tools that may be attached to your Cummins ECM. Remove any tools from in front of your Cummins ECM using a Phillips screwdriver before removing anything else from around it; otherwise, you risk damaging them on other parts inside of your vehicle's engine compartment when you open up access points for maintenance purposes later on in this process.

Open the hood of the vehicle or machine.

  • Open the hood of the vehicle or machine.

  • Locate the ECM. The ECM is usually located in the engine compartment, but not always. It may be mounted to the firewall or under the hood. The ECM is a small metal box with wires running out of it that has a bunch of stickers on it (see below).

Locate the ECM.

The first thing you should do is locate the ECM. The ECM is an electronic control module that controls all of the engine's operations, including fuel injectors and ignition timing. It can be found either in the engine compartment or under the hood. It's connected to a large connector that runs from it to other components of your vehicle's electrical system, so finding it should be relatively easy once you know where to look for it.

If you're having problems finding your ECM, look for a black box about two inches wide with two connectors coming out both sides of it (one red and one grey).

Take off the ECM cover.

  • Use a Phillips head screwdriver to remove the ECM cover.

  • Be careful not to damage or bend any pins on the ECM, which can cause it not to function properly after you reinstall it. Make sure all connectors are fully seated and don't forget to disconnect your battery before starting work!

Remove the four nuts holding the ECM in place and remove it from its mounting bracket.

  • Make sure you have a clean, well-lit work area. You'll need to be able to see what you're doing, so turn on some lights and clear off the workspace.

  • Get the right tools for the job: an adjustable wrench, flathead screwdriver, or pry bar (if needed). The adjustable wrench will be used to remove four nuts holding the ECM in place and removing it from its mounting bracket. The flathead screwdriver is used to gently pry open a tab on top of your PCM that keeps it locked in place when installed (this step is optional). The pry bar is useful if you need extra leverage while loosening your ECM's mounting nuts with an adjustable wrench; however, most people won't need this step at all!

  • Disconnect power by disconnecting any negative battery terminals (the red ones) first before attempting anything else for safety reasons! After disconnecting power safely now what? Let's connect power back up again once we've finished working on our engine control module because it controls ignition timing as well as many other important functions inside our truck."

Use pliers to disconnect the large connector that runs between the engine and the ECM.

Use pliers to disconnect the large connector that runs between the engine and the ECM. If you are not sure which connector is which, look for a label. If there is no label, use a multimeter to test for continuity between each of the connectors. The correct one will have continuity when testing from terminal A (red wire) to terminal B (black wire). If this is confusing, see our [DIY video](

Resetting an ECM requires more than just a computer reboot - you actually have to take apart your vehicle

Resetting an ECM requires more than just a computer reboot—you actually have to take apart your vehicle and rebuild it.

  • Remove the ECM from the engine compartment. You may need special tools or training, so check with your mechanic ahead of time if you can't do this yourself. If you're not sure how to remove it, ask someone who knows what they're doing.

  • Remove the cover on top of the ECM and disconnect all wiring connected to it (there should be two sets of wires). Also disconnect all electrical connections at its sides (again, two sets). Use caution when removing screws or bolts because they may be rusted or damaged by water damage over time. Make sure everyone involved wears safety gear such as gloves and goggles; use common sense about what risks are present before beginning this project!


If resetting the ECM does not work, you may have to replace it. It is possible that there is a bad connection or some other problem with the wiring harness. You can also call a professional like us at our shop to help diagnose and repair your Cummins N14 ECM reset problem.