One app for real-time data, detailed fault code information and bi-directional commands on your Cummins X15, X12, ISX, ISL 9, ISC 8.3 and ISB 6.7. Read the fault, force a DPF regen, clear a derate and get back on the road, without a trip to the dealer.
Three things every Cummins owner needs in one place: know what the code means, watch the engine live, and send the command that fixes it.
Fault code details
Quickly discover what those dash lights mean on your Cummins, what caused them, and how many times the fault has occurred, so you know whether it is a one-off or an ongoing issue.
Live data monitoring
Watch turbo boost, DPF soot load, DEF level, EGR position and exhaust temps in real time, so you catch a problem before it turns into a breakdown.
Bi-directional commands
Reset Cummins fault codes, reset aftertreatment, force a DPF regen and run an SCR performance test, the same actions a dealer charges you for, right from your phone.
Cummins | Years and engines covered
OTR Diagnostics covers Cummins engines from 2008 to 2024, including the X15, X12, ISX, ISC 8.3, ISL 9 and ISB 6.7. Not sure about yours? View the full list of supported engines below.
By the time your Cummins is parked on the shoulder in a derate, you are already paying — before anyone fixes a single thing.
The tow
A heavy-duty tow runs several hundred dollars on its own, before a tech has even looked at the engine.
The dealer wait
Then you wait for an open bay and pay a diagnostic fee just to read a code you could have read yourself.
The downtime
Every day it sits, the truck payment, the driver and the missed load still come due. A parked Class 8 earns nothing.
The repeat
A code clears but the underlying issue does not, and you pay the entire bill again a few weeks later.
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.
The part a generic dongle cannot do — watch a real Cummins fault move from triggered to resolved, without the truck leaving the lot.
Step 01
The fault triggers
The Cummins ECM throws an SPN and FMI code. On a normal day, this is the moment a dash light appears and the guessing begins.
Step 02
OTR reads it instantly
The device reads the exact fault. For fleets, the cellular unit pushes it to your dashboard the second it happens, 24/7.
Step 03
You act, remotely
Force a DPF regen, clear the derate, or decide drive versus repair — from your phone, no bay required.
Step 04
The driver keeps rolling
What would have been a multi-day dealer wait is handled in minutes. The load arrives, the truck keeps earning.
Cummins
Bi-directional commands
These are the bi-directional commands OTR sends to your Cummins, the same service actions that normally mean a shop visit. Tap any command to learn how it works:
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.
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.
Benefits:
Ensures efficiency & reliability: It maintains the DPF’s effectiveness and extends its lifespan.
SCR Performance Test
Get back to full power — faster.
The SCR Performance Test helps you verify that your emissions system is working the way it should. If your truck is stuck in a derate or throwing NOx efficiency fault codes, this test gives you the info you need to take action and move forward.
Why it matters:
Confirms your DEF system is reducing emissions properly
Helps you pass required checks after repairs
Clears the path for derate recovery
Saves time by pinpointing if a part actually needs to be replaced
Whether you just installed a new NOx sensor, replaced the SCR catalyst, or want to avoid unnecessary downtime, running this test helps you stay compliant, stay moving, and stay in control.
10,500+
Trucks running OTR Diagnostics
600+
Five-star Google reviews
6
Cummins engine families covered
16 yrs
Model years covered, 2008 to 2024
Low risk to try
Switching is the safe move
Real support from Detroit
A help center, full manuals and a phone line that reaches the people who actually build the product.
Made and assembled in-house
Designed, built and assembled in Detroit — not a reseller drop-shipping a generic box with a sticker on it.
10,500+ trucks already on it
With 600+ Google reviews, you are not the test case. You are joining an operation thousands of drivers already trust.
A membership you control
Manage or change your plan whenever you need to, on your terms.
OTR Link 2 Hardware
Unlock the full potential of your truck's diagnostics system with OTR 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.
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
Find the fault. Fix it. Keep rolling.
One truck or a whole fleet, the math is the same. Stop paying the breakdown tax and put the dealer's toolbox in your pocket.
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.
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