Fault code details

Quickly discover what those dash lights mean and know what caused the problem.

Live data monitoring

Viewing live data keeps you informed about your vehicle at any moment.

Bi-directional commands

Reset Cummins fault codes, reset aftertreatment, forced DPF regen

Instant fault code insights for Cummins engines

  • Understand your Check Engine Light: Quickly understand what those active fault codes mean with detailed information to help you know what is going on.
  • Identify the cause and take action: Get detailed explanations of fault codes specific to Cummins engines. You can use this information know what to do and how to proceed.
  • Track how many times they that fault occurred: You will see the count and be able to use that information to track if this is the first time this issue is coming on or it's an ongoing issue.
  • It doesn't just cover your engine: You will notice we cover transmission, abs, chassis, cab & body as well. We try to report to you everything that is going on with your vehicle.
Learn More about fault codes

Monitor real-time data parameters

What you can monitor:

  • Intake Pressure (Turbo Boost): Monitor turbocharger performance to gauge how your engine responds under various load conditions.
  • DPF Soot and Ash Levels: Monitor the accumulation of soot and ash to determine the optimal times for DPF regen, helping prevent DPF derates.
  • DEF Fluid Level: Keep track of Diesel Exhaust Fluid levels.
  • EGR Valve Position: Track the position of the Exhaust Gas Recirculation valve.
  • Exhaust and DPF Temperatures: Observe temperatures to manage the DPF Regen process effectively.
  • SCR Temperatures: Keep an eye on Selective Catalytic Reduction temperatures to ensure NOx reduction.
  • Engine Mileage & Hours: Track engine hours and other vital diagnostics.
  • + More: We go even beyond this list. Our goal is to supply you with data to help you monitor your vehicle in real time.
Learn More about live data

Cummins | Years and engines covered

Reset fault codes

Resetting Fault Codes: The reset of fault codes covers both active and Inactive codes.

  • Active codes: These are alerts for current issues that need immediate attention.
  • Inactive codes: These are records of past problems. They’re helpful for spotting patterns or issues that might come back again.
  • Reset all modules: We perform the reset on all the available modules that we are connected to, including transmission, body, cab & chassis systems. 

Importance of resetting codes: Clearing these codes after you fix an issue keeps the diagnostic system focused only on what’s currently active. This is crucial for verifying that repairs were successful and for maintaining accurate, up-to-date vehicle diagnostics.

Reset aftertreatment

Purpose: This essential feature enables users to reset the Engine Control Module (ECM), facilitating the regeneration of the Diesel Particulate Filter (DPF) following maintenance or replacement of exhaust system components.

Usage: The reset should only be used under severe fault conditions after necessary repairs have been made, ensuring the system is correctly recalibrated and ready for operation.

Typical repairs include:

  • Diesel Oxidation Catalyst replacement: Necessary for restoring the efficiency of emissions reduction.
  • Diesel Particulate Filter servicing or replacement: Important for removing soot build-up and maintaining exhaust flow.
  • Hydrocarbon Injector Unit repair or replacement: Critical for accurate fuel delivery to the exhaust stream, facilitating effective regeneration.

Key fault conditions:

  • 1691 (Diesel Oxidation Catalyst Efficiency Warning): Indicates reduced catalyst effectiveness.
  • 2637 (Diesel Oxidation Catalyst Face Plugged) and 1922 (Severe Diesel Particulate Filter Soot Load): Highlight significant blockages that can hinder engine performance.
  • 2638 (Diesel Oxidation Catalyst Low Efficiency) in heavy-duty engines: Signals a decline in the ability to process exhaust pollutants efficiently.

Using the Reset Aftertreatment function is vital to ensure that the aftertreatment system continues to operate efficiently and effectively after extensive repairs.

Aftertreatment maintenance filter installation

When replacing or cleaning the Diesel Particulate Filter (DPF) in a truck, it’s essential to also update the Engine Control Module (ECM).

This step ensures the truck’s computer system recognizes the new or cleaned DPF filter and adjusts the engine operations to accommodate the change, optimizing performance and emissions control.

Why notify the ECM about the new DPF?

  • Boost DPF filter efficiency: By updating the ECM, it configures the engine settings to adapt to the new or cleaned DPF, enhancing its initial efficiency and effectiveness in capturing particulate matter.
  • Forced DPF regen recommended: Post-installation, it's advisable to perform a forced DPF Regen. This process burns off any residual particles that may hinder the new filter’s functionality, ensuring optimal operation.

Forced DPF regen

The Diesel Particulate Filter (DPF) captures soot during engine operation. To clear this soot, the DPF periodically undergoes active or passive regen, usually automatically, while the engine runs.

When to use:

  • Fault codes: Some fault codes require you to run a forced DPF regen in order for certain fault codes to clear. This is because the emission system wants to run through all the system checks before the fault codes is cleared.
  • Driving conditions: If regular driving doesn't achieve the engine load and temperature necessary for active regen, then a forced DPF regen becomes essential. This is often required in situations involving excessive idling or operations under light loads.
  • High soot: If soot accumulation surpasses what normal regeneration can handle, a forced DPF regen is necessary to prevent blockages.


  • Ensures efficiency & reliability: It maintains the DPF’s effectiveness and extends its lifespan.

Nexiq Blue-Link 2 Hardware

  • Unlock the full potential of your truck's diagnostics system with Blue-Link 2 hardware.
  • Designed for seamless integration with the trucks we support, this device connects via Bluetooth, ensuring robust and reliable data transmission without the hassle of wires.
learn more about hardware
Responsive YouTube Video
Responsive YouTube Video
Responsive YouTube Video
Responsive YouTube Video
This product paid for itself on the first use. Easy to use and understand, and prevents small problems from turning into bigger problems. My favorite feature is the "Live Data". OTR Performance is a must have for any smart O/O or small fleet who wants to save time and money.
— Robert Purser - Google Review
Money well spent!! Their customer service is excellent and the diagnostic subscription is gonna save you money. Thoroughly impressed! Just imagine being able to get to a shop after you disable the derate that has you stuck on the shoulder of the highway, needing a tow for thousands.
— Calcasola - Google Review

OTR Diagnostics FAQs

How do I purchase to get started?

1. Purchase Your Package:

  • Select the quantity of vehicles and purchase the Professional Package to ensure you have everything you need.

2. Account Activation:

  • Check your email for an activation link. Use the same email address that you used for your purchase to activate your account.

3. Download the App:

  • Download the 'OTR Diagnostics' app from the Apple App Store or Google Play Store. Log in using the credentials you created during registration.

4. Need Help?

  • If you encounter any issues, feel free to reach out via email, chat, or call us at 586-799-4375.

Please note: Your OTR Diagnostics Subscription is linked to the email address used during the purchase process.

How does the subscription work?

Subscriptions are based on a 12-month auto-renew basis.

Does this app need to be online to be used?

OTR Diagnostics is bluetooth based and does require you to have Wifi or Cellular coverage for you to be able to use the app.

We do have an offline mode as a feature which does require you to have internet upon first login with the adapter connected for this to function.

It is recommended to use OTR Diagnostics with internet connected to ensure properly functionality.

Which platforms is OTR Diagnostics available for?

OTR Diagnostics works on iOS and Android mobile phones and tablets.

What does the limited lifetime warranty include?

Our OTR Diagnostics hardware is backed by a Limited Lifetime Warranty, which is a testament to our commitment to your satisfaction.

Warranty Coverage: Our Limited Lifetime Warranty covers material and manufacturing defects in our OTR Diagnostics hardware for as long as you maintain an active subscription to OTR Diagnostics. We understand that your investment in our product is significant, and we want you to be confident that it will perform as designed.

For a complete understanding of our warranty terms and conditions, please refer to the terms and conditions.

Ready to get started?

Take the quiz to discover if your OTR Diagnostics compatible.

Take the quiz Get started