Scan Tools What Can They Do

By Author: JD Durham
Total Articles: 42
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There seems to be a lot of confusion as to what scan tools can and cannot do. We will attempt to clarify this and more importantly explain what scan tools are. To understand scan tools we must first understand how they came into existence.

The US Clean Air Act of 1970 demanded more control over vehicle emissions. The Clean Air Act is a constantly evolving piece of legislation that still controls many aspects of the auto industry. Computers installed into vehicles make it easier for manufacturers to comply, since they can both adapt and monitor at the same time. These first vehicle computers went by many names such as Engine Control Module (ECM), Engine Control Unit (ECU), Engine Control Assembly (ECA) and others. Later the terminology was uniformly changed to PowerTrain Control Module (PCM) with the adoption of OBD II.

Scan Tools were produced so the manufacturer’s mechanics could access the vehicle’s computer (PCM) data ...
... to make repairs and maintain compliance with the Clean Air Act. Thus, the scan tool’s primary function is to provide the hardware connection to the vehicles PCM and allow the software to access the data relevant to maintaining emissions.

Originally, there was some reluctance by the manufacturers to installing computers and giving data access to mechanics. However, after the manufacturers started seeing the money savings from proper diagnosis, correct parts replacement, reduced labor costs, and timesavings for their customers they expanded the capabilities. They also added computers to control the Air Conditioning (HVAC), Body Control Module (BCM), and then integrated those computers into the first vehicle computer network (GM Cadillac 1984 MY).

These new computers and network could not be tested with the original scan tools (OTC Monitor 85), as they were hard programmed for PCM diagnostics only. A new generation of manufacturer scan tools (OTC Monitor 2000) was released which separated the scan tool from the software through new interchangeable software modules that would grant access to the new computers and the network. When they added a new computer or function into the vehicle, it was simply a matter of programming a new software module that could be inserted into the existing scan tool.

Unfortunately, the manufacturers failed to grasp the dynamics early enough and new scan tools were constantly needed. This has not changed even today, as the companies that build the scan tools and program the software for the scan tools at the manufacturer level are one and the same. If you need to access the Antilock Brake System (ABS), Supplemental Restraint System (air bags/ SRS), or the Transmission Control Module (TCM) the scan tool can do it but the software has to be written that allows this.

In the aftermarket, some companies chose to build the tool and focused on the tool. Others chose to focus on the software side. This division is similar to what happened in the desktop computers. The IBM type computer became the defacto standard while the Microsoft operating system became the one most of the world uses. This division allows each participant to focus on their areas of strength and provide the user with more than they would have normally received and at a tremendous savings.

The scan tool, like the 2X80S is a good functional design that has proven itself over time. Think of scan tools as if they were modems in your PC that were used to access the internet, send faxes, or provide your own in-house voicemail service. They are a dependable piece of hardware that can provide years of trouble free service.

Many software companies are stepping into the field and writing code to use the 2X80S type tools. As these companies add their products to the available programs the tool simply gets more capable. EG: The ForScan software is capable of bidirectional control similar to the Ford IDS. The VCDS Lite software allows the tool to connect at the manufacturer level on VW, Audi, Seat and Skoda vehicles.

The scan tool is both limited and limitless at the same time. Scan tools cannot look at a wiring schematic and perform diagnostics. Nor can they test a sensor without software specifically written to accomplish this. A user can watch a sensors performance on a graph looking for anomalies. This display is possible by using software like ScanMaster ELM and a 2X80S.

Scanners can be used by software to gather data, run bidirectional testing and transmit that data into a PC, which is running the manufacturers factory repair manuals, which could then make decisions based on diagnostic trees as to the cause or the most likely cause. Some manufacturers are building these systems today. Of course these systems will simply be too expensive for most outside the dealer network.

In the not too distant future, the scan tool will provide the link for software to gather and transmit data, run bidirectional tests, and access the manufacturers’ diagnostic platform that will diagnose the car including wiring schematics, sensor testing and more. This will happen with Artificial Intelligence software like “Watson” from IBM. If you think I might be wrong, consider that the auto manufacturers have over 30 years of data to use in building great AI powered systems.

The 2X80S obd2 scan tool can do many diagnostic procedures; it simply must have the software to perform the required task on a vehicle capable of supporting that level of diagnostics.

Copyright © 2012 JD Durham

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