Caterpillar Engine Diagnostic Scanners

Written by the YOUCANIC technicians in Towson, Maryland, from the UCAN-HD-A coverage database and our own shop work. Updated October 24, 2026.

Caterpillar stopped building engines for other truck makers after 2010, which is exactly why the trucks still running a C7, C13, C15 or 3406E need a tool that still talks to them without a dealer visit. A Cat engine ECM holds the injector trim files, the aftertreatment counters on the ACERT era engines and the maintenance indicator, and a generic heavy duty code reader shows you fault codes and stops there. The tools below are what we use to read a Cat engine on J1939 or J1708, run the regeneration and trim routines, and get the truck back on the road. The coverage database behind the UCAN-HD-A lists Caterpillar engine families by name, from the 3116 and 3126 of the 1990s GM and Freightliner medium duty trucks to the C7, C9, C11, C13, C15 and C18 of the 2000s, each as a truck entry with its own J1708 and J1939 versions. Pick by what you need to do.

Which Scanner Do I Need For A Caterpillar Engine?

CLASS 4 TO 8 TRUCKS, BUSES, ENGINES AND EQUIPMENT

UCAN-HD-A

Full system heavy duty scanner on SAE J1939, J1708 and J1587 with a wireless VCI and the Deutsch connector kit in the case. Reads and clears every module the truck reports, runs active tests and the Caterpillar special functions: manual and ash service regeneration, aftertreatment recovery, injector trim calibration, NOx sensor and EGR tests, maintenance indicator reset. Free updates, no subscription.

PICKUPS, VANS AND CARS

UCAN-II Pro, new or open box

The light duty full system scanner for the pickups, vans and cars in the same fleet, with lifetime free updates and a built in TPMS module. It does not cover the Caterpillar engine families; if your work is the trucks, start with the UCAN-HD-A above.

What The UCAN-HD-A Does On A Caterpillar Engine

• ✓ Identifies the engine family and reads ECU information, fault codes and live data on the 3116, 3126, 3126B, 3176, 3176B, 3406B, 3406C, 3406E, C7, C9, C-10, C11, C-12, C13, C-14, C15, C-16 and C18 truck entries
• ✓ Manual Diesel Particulate Filter Regeneration and Ash Service Regeneration on the engines with aftertreatment, with the soot load, exhaust temperature and differential pressure on screen while it runs
• ✓ Aftertreatment Recovery Procedure after an aftertreatment repair, and the Aftertreatment NOx Sensor Functional Test
• ✓ Injector Trim Calibration after replacing injectors, so the ECM runs the new trim files instead of the old ones
• ✓ EGR System Test and the engine active tests the database lists for the family
• ✓ Maintenance Indicator, the service interval the ECM counts down
• ✓ The Air Inlet Shutoff versions of the C-9, C-10, C11, C-12, C13, C-14, C15, C-16, C18, 3126 and 3406E, and the gas and diesel dual fuel versions of the C-10, C-12 and 3126, are listed as their own entries, as are the GM 530, 540 and 560 chassis versions of the 3126, C7 and C9
• ✓ Live data with graphing, PID merge and recording, and PDF reports from the tablet

Service Functions By Job On A Caterpillar Engine

On the tablet you pick the engine entry, then the function category, then the routine. The Caterpillar database uses the categories ECU information, Read codes, Erase codes, Live data, Active test and Special Functions. These are the routines the coverage database lists, grouped by the job you are doing. Names are as they appear on the tablet. Coverage varies by engine family and ECM software, so check yours before you order.

What The Scanner Sees On A Caterpillar Engine

The Caterpillar database is organized by engine family rather than by truck model, with 3,898 named entries covering truck, industrial, marine and genset versions. These are the on highway entries you will pick from on the tablet; each one gets fault codes, live data and, where the database shows it, the active tests and special functions above.

Symptom, Then The Routine That Fixes It

• DPF restriction warning or a derate on a C13 or C15 with aftertreatment: Manual Diesel Particulate Filter Regeneration in Special Functions, with the differential pressure on the live data screen to confirm it worked.
• Filter just cleaned or replaced and the warning stays: Ash Service Regeneration, then the Aftertreatment Recovery Procedure to bring the system out of its protected state.
• Rough running or an injector code after new injectors on a C7, C9 or 3126: Injector Trim Calibration, entered per cylinder from the trim file on the new injector.
• NOx sensor code after an aftertreatment repair: Aftertreatment NOx Sensor Functional Test to prove the sensor before you buy another one.
• EGR code or black smoke on an EGR engine: EGR System Test from the engine entry.
• Service light after an oil change: Maintenance Indicator in the engine entry.

Frequently Asked Questions

Will it run a forced regen on my C13 or C15?

Yes. Manual Diesel Particulate Filter Regeneration and Ash Service Regeneration are listed in the Caterpillar special functions, along with the Aftertreatment Recovery Procedure for after the repair. Confirm your engine serial number in the coverage checker first, because the regeneration routines apply to the engines built with aftertreatment.

Can it calibrate injector trim on a C7 or a 3126 after new injectors?

Yes. Injector Trim Calibration is in the special functions list, and the C7, 3126 and 3126B truck engines each have their own entries in the database, including the GM 530, 540 and 560 chassis versions used in the Kodiak and TopKick medium duty trucks.

My truck has a 3406E or an older 3126 on the 6 pin connector. Does it still connect?

Yes. The 3406B, 3406C, 3406E, 3176, 3176B and 3116 truck engines are listed, and the kit includes the 6 pin Deutsch connector for J1708 along with the 9 pin for J1939, so the older trucks plug in without an extra adapter.

Does it flash the ECM or change the parameters that need a password?

No. Flash files and the password protected parameters need Cat ET with a dealer license. The UCAN-HD-A does diagnosis, live data, active tests and the special functions listed above.

Does it cover Caterpillar equipment and marine engines too?

The same database carries industrial, genset and marine entries for the C-series, the 3126B used in Cat machines and the 1100, 1200, 1500, 1700 and 2200 series engines, which is why it has 3,898 named entries. Check the exact machine on the coverage checker; the truck entries above are the ones this page is about.

How do I know my exact engine and routine are covered?

Use the coverage checker by engine family, or call 1-888-959-4265, Monday to Friday 9 AM to 4 PM Eastern, with the engine serial number and the chassis, and a technician will tell you plainly. If it does not do what you need, we will say so. Every scanner also comes with 31 day returns, no questions asked.

Working on a different truck or engine? See the scanners by make hub, the service functions explained one job at a time, and the step by step repair guides on youcanic.com.