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: Compare Coverage, Kits and Licensing
Compare exact vehicles, service functions, included hardware and license scope. Current JPRO coverage includes off-highway applications.
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: Lookup and Diagnostic Tools
To look up a Cummins ISX fault, record the engine serial number, ECM code, Cummins fault number and complete SPN/FMI when available,…
Guide
Detroit DD15 Fault Codes: Lookup and Diagnostic Tools
Record the complete Detroit fault and engine generation, then use the matching manufacturer troubleshooting procedure.
Guide
Cat C15 Fault Codes: Lookup and Diagnostic Tools
To look up a Caterpillar C15 fault, record the engine serial number, ECM identity and the exact Cat ET diagnostic or event…
Guide
PACCAR MX-13 Fault Codes: Lookup and Diagnostic Tools
To look up a PACCAR MX-13 fault, record the VIN, engine identity, emissions configuration and complete DAVIE fault text, then use the…
Guide
Mack MP8 Fault Codes: Lookup and Diagnostic Tools
To look up a Mack MP8 fault, record the Mack VIN, engine identity, controller and software version, then use the matching manufacturer…
Guide
Volvo D13 Fault Codes: Lookup and Diagnostic Tools
To look up a Volvo D13 fault, record the Volvo truck VIN, engine identity and the reporting controller, then use the matching…
Guide
International A26 and MaxxForce Fault Codes: Lookup Guide
Identify the engine, controller and complete fault before choosing a procedure. The A26 is MAN D26-based, not a Detroit DD13 derivative.
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