In the automotive aftermarket world, there are three types of scan tools available for shops: OBD-II generic, OBD-II enhanced and factory scan tools.
While some shops may purchase a factory scan tool for a specific OEM make, many shops opt for the broad coverage and relatively lower price point of an aftermarket scan tool - whether it be OBD-II generic or OBD-II enhanced.
Put simply, the difference between OBD-II generic versus OBD-II enhanced scan tools is that generic scan tools only provide emissions-based information on the vehicle.
“Generic OBD-II is limited to PCM or engine data,” says Launch Tech USA’s vice president of diagnostics Harlan Siegel. He discusses that enhanced scan tools provide additional information on vehicle computer modules. “When you get into enhanced (scan tools), you get into things other than engine, such as transmission, ABS, SRS (airbags), HVAC and more. Some of these cars have north of 75 modules.”
“The more modules and bidirectional testing a tool offers, the more successful a tech will be in using it to repair vehicles,” says Michael Flink, national sales manager – commercial, Autel North America.
OBD-II enhanced scan tools also may have some or all of the same functionalities of an OBD-II generic tool, while also providing access to OEM-specific information. Ed Lipscomb, OTC senior product manager of global diagnostics, explains that techs may require OBD-II generic data in some instances, but also will need OEM-enhanced information.
“The largest difference as far as the data that you get, is that the OEM enhanced will include bidirectional tests that the OBD-II generic will not,” says Lipscomb. With bidirectional testing, there are two actions that technicians can perform with an OEM-enhanced scan tool: actuator tests and adjustments.
Bidirectional actuator tests allow the technician to complete an action on the vehicle, via the scan tool. This means turning on headlights or blowing the car horn.
According to Lipscomb, bidirectional adjustments work to access a function or area of the vehicle, also known as coding, that “will be different when you disconnect the tool, than when you connected it. You are actually making an adjustment to the car.”
Another function of some enhanced scan tools is reprogramming, also known as J2534 reflashing.
“J2534 programming is an SAE standard that permits the automotive aftermarket to reprogram a vehicle’s computer if the drivability or the problem with the vehicle that you’re trying to fix is specific to the calibration or to the computer program. The only way to fix something if the program goes bad, is to reprogram it,” says Lipscomb. “It’s a standard that allows the aftermarket to take OEM computer files, and replace the files on a vehicle’s computer, if that file is defective.”
Heavy duty scan tools
New for 2015, the PTEN Scan Tool Spec Guide now includes information on heavy duty aftermarket vehicle coverage.
OTC’s heavy duty diagnostics representative Matt Stein says there are different criteria to select when diagnosing these types of vehicles. “Customers are able to choose the chassis, engine, transmission and brake systems. Heavy duty scan tools need to cover this different set of vehicle systems that automotive tools do not.”
“The heavy duty standard and the protocols or language those vehicles use is completely different than OBD-II and light duty. The features are similar though, often with different names,” says Autel's Flink. “Look for heavy duty tools that list various manufacturers of systems in their coverage. Unlike light duty, these vehicles are not done by year, make and model, but by the manufacturer of the engine, transmission or brake system, etc.”
Flink explains that medium duty vehicles (Classes 3 through 6) can sometimes cause confusion because they may include both OBD-II protocols as well has heavy duty protocols, depending on the vehicle.
“A shop working on a variety of medium duty vehicles should be prepared to have both a strong OBD-II tool and a strong heavy duty tool,” says Flink.
