Jaltest Off-Highway Vehicle Diagnostics
Off-highway equipment operates in the harshest conditions on earth: quarries, mine sites, pipeline corridors, logging operations, demolition sites, and construction zones where downtime is measured in thousands of dollars per hour. Jaltest off-highway diagnostics provide OEM-level diagnostic access across 199 manufacturers, 4,109 models, 8,437 technical data entries, and 3,553 interactive wiring diagrams, updated three times per year as new machines and new electronic systems enter the market.
Whether your fleet includes excavators, wheel loaders, bulldozers, graders, articulated haulers, cranes, skid steers, telehandlers, or stationary engine-driven equipment, Jaltest gives your technicians the same diagnostic depth that factory service tools provide. One platform replaces the stack of brand-specific tools that would otherwise cost your operation hundreds of thousands of dollars.
Off-Highway Subcategories
Jaltest off-highway coverage spans five major subcategories. Each has its own collection page with detailed manufacturer and capability information.
Heavy Equipment
Excavators, bulldozers, wheel loaders, motor graders, articulated haulers, crawler cranes, rough terrain cranes, pavers, milling machines, and mining trucks from 30+ manufacturers including Caterpillar, Komatsu, Volvo CE, John Deere, Hitachi, Liebherr, JCB, and Doosan. This is the core of off-highway diagnostics, covering the iron that moves earth, lifts loads, and builds infrastructure.
See full heavy equipment coverage and manufacturer details
Compact Equipment
Mini excavators, skid steer loaders, compact track loaders, compact wheel loaders, and compact backhoe loaders from 13+ manufacturers including Bobcat, Caterpillar, Kubota, John Deere, JCB, Takeuchi, and Wacker Neuson. Compact equipment has become increasingly electronic, with Tier 4 Final engines, CAN bus-controlled hydraulics, and telematics systems that all require diagnostic access.
See full compact equipment coverage
Stationary Engines
Diesel and gas engines used in power generation, pumping stations, compressors, and industrial applications from 15+ manufacturers including Caterpillar, Cummins, Deutz, John Deere, Perkins, MTU, Volvo Penta, and Yanmar. These engines run in data centers, hospitals, mining operations, oil and gas facilities, and anywhere reliable backup or primary power is required.
See full stationary engine coverage
Multi-Purpose Vehicles
Utility vehicles, airport ground support equipment, and specialty off-highway machines that do not fit neatly into other categories. Coverage includes turf care equipment, airport pushback tractors, ground power units, and multi-terrain vehicles used in municipal, industrial, and military support applications.
Airport Equipment
Ground support equipment (GSE) at airports, including baggage tractors, belt loaders, pushback tugs, ground power units, and de-icing vehicles. These machines operate on tight schedules with zero tolerance for delays. Jaltest covers the diesel engine, transmission, and hydraulic systems on supported GSE platforms, allowing airport maintenance crews to diagnose and repair equipment without waiting for specialized service contractors.
Full Diagnostic Capabilities
Jaltest off-highway diagnostics provide the following capabilities across all supported manufacturers and equipment types.
Fault Code Reading and Clearing
Read active, stored, and pending diagnostic trouble codes from every electronic control unit on the machine. Off-highway equipment typically has separate ECUs for the engine, transmission, hydraulic system, machine control, aftertreatment, and telematics. Jaltest reads them all in a single diagnostic session and displays OEM-specific fault code descriptions, not generic J1939 translations.
DPF Regeneration
Tier 4 Final off-highway engines use diesel particulate filters that require periodic regeneration. Off-highway equipment often operates at idle or low load for extended periods (crane work, finish grading, pump station duty), which prevents automatic DPF regeneration. Jaltest initiates forced stationary regenerations, monitors soot loading levels, checks exhaust temperatures during the process, and resets regeneration counters. This is one of the most frequently used diagnostic functions on off-highway equipment.
Injector Coding
Common rail diesel injectors on off-highway engines require calibration codes to be entered into the ECU after replacement. Jaltest handles injector coding for Caterpillar, Cummins, Deutz, Volvo, FPT, Perkins, Yanmar, and other engine platforms used in off-highway applications. Without proper injector coding, the engine may run rough, produce excessive emissions, or set persistent fault codes.
Cylinder Cut-Out Testing
Isolate misfiring or underperforming cylinders by sequentially disabling fuel delivery to each cylinder while monitoring engine RPM drop and smoothness. This test identifies faulty injectors, low compression cylinders, or valve timing issues without removing any components. On a 12-cylinder mining truck engine, this saves hours of diagnostic time.
Hydraulic and Transmission Calibrations
Off-highway equipment relies on complex hydraulic and transmission systems that require calibration after component replacement or when performance degrades. Jaltest performs hydraulic pump flow calibrations, valve spool calibrations, transmission clutch fill-time calibrations, and torque converter lockup adjustments. These are functions that equipment dealers charge $500 to $2,000 per calibration to perform.
Parameter Changes
Modify ECU-stored parameters to configure machine behavior: engine speed limits, idle settings, hydraulic response rates, auto-idle timers, cold-start warmup profiles, and machine attachment configurations. Jaltest gives you the same parameter access as the factory service tool, allowing you to set up machines for specific job site requirements without a dealer visit.
Maintenance Resets
Reset service interval counters, oil life monitors, filter change indicators, and other maintenance-triggered alerts after performing scheduled service. Off-highway equipment maintenance intervals are typically tracked electronically, and failing to reset these counters can trigger nuisance warnings or restrict machine operation.
Bi-Directional Commands and Actuator Tests
Activate and control individual components from the diagnostic tool: cycle hydraulic valves, actuate solenoids, test warning lights and buzzers, operate cooling fans, trigger turbo actuators, and exercise DEF dosing pumps. Bi-directional commands allow you to verify component operation without rigging up test equipment or jumper wires.
Generator Set Diagnostics
For stationary engine applications driving generators, Jaltest provides engine diagnostics alongside generator-specific parameters: voltage output, frequency, load percentage, transfer switch status, and paralleling controls. This is critical for data center backup power, hospital emergency systems, and mining site power generation.
Interactive Wiring Diagrams
Access 3,553 interactive wiring diagrams for off-highway equipment. Trace circuits from the ECU to the sensor, identify connector pin assignments, locate splice points, and find ground locations. Off-highway wiring harnesses are subjected to vibration, moisture, dust, and temperature extremes that cause failures. Interactive diagrams reduce the time spent tracing wires through a 50,000-pound machine from hours to minutes.
Coverage by the Numbers
| Metric |
Count |
| Manufacturers covered |
199 |
| Models covered |
4,109 |
| Technical data entries |
8,437 |
| Wiring diagrams |
3,553 |
| Software updates per year |
3 |
Why Multi-Brand Diagnostics Matter for Off-Highway
No other equipment sector has as many manufacturers as off-highway. A single construction site might have Caterpillar excavators, Komatsu wheel loaders, Volvo articulated haulers, JCB telehandlers, and a Cummins-powered generator. A mining operation might run Hitachi excavators, Caterpillar haul trucks, Liebherr cranes, and John Deere dozers. A rental company might have equipment from 15 different manufacturers in its yard on any given day.
The cost of purchasing factory diagnostic tools for each of these manufacturers is staggering. Cat ET alone runs $3,000 to $8,000 plus annual subscriptions. Komatsu KCESS, Volvo VCADS, Hitachi Dr. ZX, and John Deere Service Advisor each add thousands more. For a fleet that includes 10 equipment brands, you are looking at $30,000 to $80,000+ in diagnostic tooling before your technician runs the first test.
Jaltest covers 199 off-highway manufacturers in a single platform. The economics speak for themselves.
Who Uses Jaltest Off-Highway Diagnostics
Construction Companies
Your fleet works on job sites miles from the nearest dealer. When an excavator sets a fault code, you need to diagnose it with the service truck you already have on site. Jaltest gives your field mechanic the same diagnostic access the dealer tech would bring, without the $200+/hour service call and the 24-hour wait.
Mining Operations
Your equipment runs 20 hours a day, and every hour of downtime is measured in tons of material not moved. Jaltest provides the diagnostic access your maintenance crew needs to keep machines running: DPF regeneration on haul trucks, hydraulic calibrations on excavators, transmission diagnostics on wheel loaders, and engine management across every brand in your fleet.
Equipment Rental Companies
You rent equipment from a dozen manufacturers, and it comes back from job sites with fault codes, pending maintenance alerts, and intermittent problems that need diagnosis before the next rental. Jaltest covers your entire rental fleet with one tool, allowing your shop to turn equipment around faster and reduce the number of machines sitting in the "needs diagnosis" row.
Municipal and Government Fleets
Your fleet includes motor graders, wheel loaders, backhoes, and utility vehicles from multiple manufacturers acquired through different procurement cycles. Jaltest gives your maintenance department diagnostic independence from dealer service, reducing per-machine service costs and improving equipment availability.
Independent Heavy Equipment Mechanics
You work on whatever rolls into your shop or breaks down on a job site. Cat, Komatsu, Deere, Volvo, JCB, Doosan. Your customers expect you to fix all of them. Jaltest makes that possible with one diagnostic platform instead of six.
Subcollections
Get Started with Off-Highway Diagnostics
Diesel Truck Diagnostic Tools has been an authorized Jaltest/Cojali dealer since 2016. We understand the demands of off-highway equipment maintenance and have equipped hundreds of construction, mining, rental, and municipal operations with the diagnostic tools they need to keep iron moving.
Browse the off-highway diagnostic kits below, or call 800-217-0063 to speak with a trained staff who can help you choose the right package for your fleet. We will verify coverage for your specific equipment and recommend the diagnostic kit that fits your operation.
Email: support@dieseltruckdiagnostictools.com | Phone: 800-217-0063 | Monday-Friday, 8:00 AM - 5:00 PM CST
Free ground shipping on every order. Full manufacturer warranty included.
