Tool Review: Cojali Jaltest

April 10, 2020
Plug-and-play functionality and attention to detail elevate this diagnostic system in the reviewer’s eyes.

Heavy duty commercial vehicles are typically more complex than passenger cars. Heavy duty trucks, for instance, are far more customizable; a truck can have an engine from any number of engine manufacturers, a transmission from multiple transmission manufacturers, a brake system from a selection of brake manufacturers — the combinations are seemingly endless.

This complex nature can make diagnosing any of these systems complicated, to say the least. That’s why Dax Acor, shop lead at FleetPride in Idaho Falls, Idaho, finds Cojali’s Jaltest diagnostic system to be such a time saver for his shop.

“It's a plug-in-and-identify-everything kind of deal,” Acor says. “[Jaltest] self-identifies every module on the truck. With Volvos, it'll bring up like 16 or 17 modules. Peterbilts will have seven or eight. Then it goes engine, transmission — you get a Bendix or Meritor brake identification and ... it's almost easier to hook up and identify what kind of systems you have versus getting on a creeper and looking for the module.”

As the Jaltest software identifies each module, Acor says it also pulls any codes from each one and condenses the information into a user-friendly page.

“It ... links to each module and then pulls the codes, then [links to] the next module and pulls the codes ... and then it brings up one full home screen of all the modules that you have,” he says.

In addition to providing fault codes, Acor says Jaltest allows him to test any number of vehicle systems as well.

“You can test functions [such as] exterior lights; you can turn on an individual front left blinker for instance,” he says. “If the light works, you can command it on [from] the computer and you know the wiring's good. If it doesn't [work], you could have a bulb or a wiring problem, so it helps with things like that. You can actuate the blower or actuate HVAC blend doors; you can cycle those and you can watch them. If there's a module that actuates it, you can pretty much test it.”

If Acor is not able to figure out what is causing a problem on his own, he uses the Jaltest troubleshooting tool. It provides pinout diagrams, wire numbers, schematics — virtually anything necessary to work on the truck, he says.

“It's very vehicle specific,” he says. “They use live pictures rather than [illustrations]. That shows willingness on their end to put forth their time to make it that way.”

Acor says that in addition to the troubleshooting tool, the Jaltest software contains training videos, frequently asked questions, and other resources to help technicians become familiar with the system’s functionalities. And, as with any diagnostic software, updates are vitally important to keep technicians up-to-date with the latest information.

“We get quarterly updates that we download,” he says. “Each one comes with a four- or five-minute video of what's new, what you can expect to see coming in the next update — kind of a little teaser. It's pretty cool the time and effort they put into doing those updates and making them available for us.”

The attention to detail the company puts into their product and the plug-and-play simplicity of its use make Jaltest an easy choice for Acor and his team.

About the Author

David Brierley | Editor | Fleet Maintenance

David Brierley is the editor of Fleet Maintenance magazine.

Brierley’s education and career have been based in the publishing industry. He is an award-winning writer and comes from a background in automotive, trucking, and heavy equipment. Brierley joined the Endeavor Business Media vehicle repair group in 2017 as managing editor for Fleet Maintenance, PTEN, and Professional Distributor magazines, as well as In his current role, he writes for and oversees production of Fleet Maintenance magazine. He has worked in the publishing industry since 2011.

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