Scan Tools
How to Choose the Right Heavy-Duty Scan Tool
There is no single best HD scan tool. The right tool matches the engines, model years, and depth of work your shop…
Long-form guides
Buyer guides & tech walkthroughs.
Pick the right tool the first time. Each guide is written by a senior diesel tech and updated for current model years.
Buying decisions
Pick the right tool for your bay.
If you're sizing up a purchase or comparing platforms, start here.
OEM Software
OEM vs Aftermarket Diagnostic Software: What Heavy-Duty Shops Actually Need
OEM software wins on parameter writes, reflashes, ash resets, and late-model coverage. Aftermarket wins on multi-make coverage and total cost. Most shops…
Fleet Diagnostics
Best Diagnostic Tools for Mixed Fleets
Independent shops solve mixed-fleet coverage with one solid multi-brand platform plus one or two OEM titles for the brands they see most.…
Diagnostic Kits
Laptop Kit vs Software Only: Which Diagnostic Setup Should Your Shop Buy?
A bundled kit is a markup, but it is also a guarantee that the laptop, OS, drivers, adapter, and license were tested…
Guide
Heavy Duty Scan Tool Comparison 2026 | HDT
No single scan tool covers Class 3-8 across every OEM at dealer-level depth. That tool doesn’t exist in 2026 and hasn’t for…
Guide
JPRO vs Jaltest — Honest 2026 Comparison | HDT
JPRO and Jaltest are the two strongest aftermarket multi-brand diagnostic platforms in 2026 North American HD service. Most shops can only afford…
Guide
Dealer-Level vs Aftermarket Diagnostic Tools | HDT
“Dealer-level” gets used as a marketing word more than a technical one. Inside a dealer service bay, dealer-level means the OEM’s full…
Guide
Fleet Diagnostic Tool Buying Guide — Multi-Bay Setups | HDT
Buying diagnostic tools for a fleet maintenance operation is a different problem than buying for an independent shop. The decision isn’t “which…
Guide
Mixed Fleet Diagnostic Tools | Class 3-8 All-Makes | HDT
If you wrench on Cummins on Monday, Detroit on Tuesday, PACCAR Wednesday, and a Volvo or Mack by Thursday afternoon, you don’t…
Guide
Authorized Reseller vs Gray Market HD Software | HDT
Search “Cummins INSITE” on eBay, AliExpress, or any of the lesser-known forums and you’ll find listings at $49, $99, $200 that look…
In-bay walkthroughs
Procedures & troubleshooting.
When the truck is on the hook and the dash is yelling. Senior-tech procedures for the situations that show up in real bays.
DPF & Emissions
What You Need for DPF Regens: Tools, Procedures, and What Actually Works
A forced regen burns soot. It does not remove ash. A reliable setup needs the right interface, live aftertreatment data, the ability…
Guide
How to Diagnose Cummins Fault Codes — Tech Workflow | HDT
A fault code is a starting point, not a diagnosis. Cummins ECMs throw codes for symptoms, not root causes — a single…
Guide
Heavy Duty ABS Diagnostic Tools — Bendix, WABCO, Haldex | HDT
Heavy-duty ABS isn’t optional anymore. Class 6-8 tractors require electronic stability control, trailer ABS is a federal mandate, and the consequence of…
Fault-code references
Engine fault-code guides.
Active-code references for the major heavy-duty engine families — what the codes mean and where to start.
Guide
Cummins ISX Fault Codes Reference (Top 20) | HDT
Cummins ISX and X15 share most of their fault code architecture. The codes below are the 20 we see most often across…
Guide
Detroit DD15 Fault Codes Reference (Top 20) | HDT
Detroit DD13, DD15, and DD16 engines (and the related International A26 derivative) share most of their fault code architecture across model years.…
Guide
Cat C15 Fault Codes Reference (Top 18) | HDT
Caterpillar C15 (and the smaller C13, larger C16) was Cat’s last on-highway HD lineup before Cat exited US Class 8 in 2010.…
Guide
PACCAR MX-13 Fault Codes Reference (Top 15) | HDT
PACCAR MX-13 and MX-11 engines power most modern Kenworth T680/T880 and Peterbilt 579/567 chassis. The 15 codes below are the ones that…
Guide
Mack MP8 Fault Codes Reference (Top 18) | HDT
Mack MP8 (and the smaller MP7) power most modern Mack Anthem, Pinnacle, Granite, and Pi vocational trucks. Mack and Volvo share the…
Guide
Volvo D13 Fault Codes Reference (Top 18) | HDT
Volvo D13 powers most Volvo VNL, VNR, and VHD trucks built since 2007. The D11 (smaller regional) and D16 (heavy vocational /…
Guide
International A26 & MaxxForce Fault Codes Reference | HDT
International HD trucks run two distinct engine families: the current A26 (Detroit DD13 derivative, in production since 2017) and the discontinued MaxxForce…
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