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Cummins
X15 X12 ISX ISC 8.3 ISL 9 ISB 6.7 2008 – 2024

Turn a $2,000 derate day
into a 20-minute fix.

Read the fault, run the fix and clear the derate yourself, from the cab, on your phone, with Cummins dealer-level commands. No tow. No diagnostic fee. No two-day appointment.

60-day money-back guarantee Adapter included free Built in Detroit, MI
Key features
  • Reset a derate
  • Forced DPF regen
  • Read & reset fault codes
  • SCR performance test
  • Aftertreatment filter install
  • OTR Assist AI
  • Live data monitoring
All included on every plan, plus the OTR Link 2 adapter, free.
Cummins commands · priced in what they save you

Replace a bill you've already paid before.

These aren't features. They're invoices you stop receiving. Average costs below are what members report paying shops and dealers before switching.

1 Clear a derate from the driver's seat Command: Reset Aftertreatment Avoids on average $1,300 tow

A 5-MPH SCR derate is the most expensive fault a Cummins throws, not because of the part, but because you can't get to the shop without a hook. Reset the derate from the cab, restore full power, and drive to the fix on your terms.

How it plays out: SPN 5246 hits on a Sunday. The old way: $1,300 tow plus waiting for Monday. With OTR: reset the inducement, finish the load, schedule the repair yourself.
2 Burn off soot yourself Command: Forced DPF Regen Replaces a $300 shop regen

When soot loads up and a passive regen won't cut it, the shop charges ~$300 and half your day to do what your engine can do parked. Run a forced regen in 30–45 minutes while you eat lunch.

Our most-used command: members have completed 100,000+ forced regens with OTR Diagnostics.
3 Read & reset faults before anyone charges you Command: Reset Cummins Fault Codes Skips the $400 diagnostic fee

Shops charge ~$400 on average just to plug in and tell you what you could see yourself. Read the fault, see what it means in plain English, clear it after the fix, and only pay a shop when there's actual wrench work.

Know before you go: half the battle is knowing whether it's a $40 sensor or a real repair.
4 Test your SCR before it derates you Command: SCR Performance Test Prevents the next $2,000 surprise

The SCR system fails slowly, then derates you suddenly. Run the same performance test the dealer runs and catch a dying NOx sensor or DEF issue weeks before it becomes an inducement on a load.

Maintenance, not emergency: you pick when and where the repair happens.
5 Install your own aftertreatment filter Command: Aftertreatment Maintenance Filter Installation Ends the dealer-only visit

Swapping the DPF at a maintenance interval is a bolt job, but the ECM needs to be told it happened, and dealers charge a visit for that handshake. Do the install, run the command, done.

DIY maintenance stays DIY, no appointment just to close out your own work.
+ Tap any command to see how it plays out on the road
Dollar figures are member-reported averages for tows, dealer diagnostic fees, and shop regens. Your rates vary by region, which is exactly why doing it yourself wins everywhere.
The math on one bad day

One derate. Two ways it can go.

Without OTR Diagnostics

Tow to the dealer (average)$1,300
Diagnostic fee (average)$400
Forced regen at the shop$300
1–2 days of missed loads$800 – $1,600
The old way$2,800 – $3,600

With OTR Diagnostics

Read fault + root cause on your phone$0
Reset aftertreatment derate from the cab$0
Forced DPF regen, parked, 30–45 min$0
Deliver the load, schedule the real fixOn your terms
Membershipfrom $1.09/day
Handled in 20 minutes
Why our fault data is different

We've logged 22 million fault codes. Yours won't surprise us.

  • Pattern-backed answers. When SPN 4364 shows on an X15, OTR Assist AI draws on the thousands of times our members have already hit it, what caused it, what fixed it, what it cost.
  • 1,000,000+ commands sent, 100,000+ regens run. Every forced regen and derate reset sharpens the guidance for the next driver. A code reader shows you a number; OTR shows you what 10,500 members did about it.
  • Cummins-specific depth. X15, X12, ISX, ISC 8.3, ISL 9 and ISB 6.7, 2008 to 2024, including the aftertreatment-era engines that generate most of the pain.
Most-logged Cummins faults · OTR member network
SPN 4364 · NOx Conversion EfficiencyUsual fix: outlet NOx sensor / DEF quality
1,000s logged
SPN 3712 · SCR InducementUsual fix: resolve parent fault, reset derate
1,000s logged
SPN 5246 · SCR Derate ActiveUsual fix: reset from cab, repair on schedule
1,000s logged
SPN 3251 · DPF PressureUsual fix: forced regen · check DPF loading
1,000s logged
Reflects aggregated, anonymized fault data across the OTR member network.
Live data · watch problems form before they park you

The gauges Cummins didn't put on your dash.

DPF Soot & Ash LevelsThe one that matters: regen at 80% on your schedule, not at 100% on the road's
SCR & Exhaust TemperaturesSpot a lazy aftertreatment system before the NOx faults start
DEF Fluid Level & Quality SignalsBad DEF is the #1 avoidable cause of inducements
Intake Pressure (Turbo Boost)Falling boost = money burning as unburned fuel
EGR Valve PositionCatch a sticking valve before it cascades into derates
Engine Mileage & HoursReal usage data for maintenance intervals and resale proof
Cummins owners on OTR · 4.78★ from 600+ Google reviews

Proof from the people paying the bills.

★★★★★ Verified

"X15 threw an SCR derate 400 miles from home. Reset it from the cab, delivered, and fixed the NOx sensor in my own driveway for $40. The dealer quoted $1,900 and a Thursday."

Robert P.Owner-operator · Cummins X15
★★★★★ Verified

"I run three ISX trucks. Between regens and code-reads alone this pays for itself every quarter. The shop was getting $300 every time a soot light came on."

M. CalcasolaSmall fleet · Cummins ISX
★★★★★ Verified

"Had a 5 MPH derate in the middle of Nebraska at 11pm. Twenty minutes with my phone and I was rolling again. A tow out there is $1,300 minimum."

Danny W.Owner-operator · Cummins X15
★★★★★ Verified

"The SCR performance test caught a bad DEF dosing unit before it ever put me in derate. Fixed it on a Saturday at home instead of losing a Tuesday load."

Luis M.Owner-operator · Cummins ISX 15
★★★★★ Verified

"I'm 61 and not a computer guy. Plugged it in, app found my ISB, and it told me in plain English what the code meant. Took five minutes."

Gary T.Owner-operator · Cummins ISB 6.7
★★★★★ Verified

"Stopped paying $400 every time a light came on just to be told it was nothing. I check it myself now and only go to the shop when there's real work."

Andre B.2-truck fleet · Cummins X12
Get started

Your Cummins is covered.
The next derate doesn't have to cost $2,800.

Every plan includes the OTR Link 2 adapter free ($299 value), all Cummins commands above, OTR Assist AI, live data, and US-based support from Detroit.

Single Truck Pro$399/yr · $1.09/day
Unlimited Truck Pro$599/yr · any VIN
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