Ordinary scan tools for reading engine fault codes are usually no help when it comes to reading fault codes or doing other diagnostics on antilock brake systems. It takes special software to access the ABS diagnostics, which usually means using a factory scan tool, a high end professional scan tool, a dedicated ABS tester, or a DIY scan tool with dual capabilities.

A scan tool that can read ABS codes can help you identify faults to figure out why the ABS warning light is on, but a code by itself does not tell you which part needs to be replaced. Further testing is usually needed to isolate and identify the fault that is causing the problem.

What's more, intermittent problems may not set a fault code. So if there is no code, you cannot assume everything is fine. You have to check the operation of the system as well as individual components to figure out what is wrong.

Factory scan tools and high end professional scan tools have bi-directional capability that allows them to run various ABS system self-tests to help detect faults. The scan tool may also cycle the ABS solenoids to make bleeding the brakes easier. Most entry level ABS scan tools have little or no bi-directional capability and cannot run these tests.

Point by point resistance and voltage checks can help you isolate problems with or without codes, but such tests can be very time-consuming and may not always reveal a problem. Dynamic tests are also impossible with this approach because you have no means of exercising or testing the operation of the ABS solenoids and valves. Such components may show the correct voltage and resistance readings, but may not be functioning correctly. So some means of testing their function may be necessary for an accurate diagnosis. That is where a bi-directional scan tool or dedicated ABS tester can make a big difference.

New Equus INNOVA Scan Tools Now Include ABS Capability

Equus now offers two of its scan tools with software that can also access antilock brake codes. The INNOVA 3150 ABS Scan Tool is for the Do-It-Yourselfer who wants more than just a basic code reader. The tool can access OBD II codes on most 1996 and newer vehicles, import and domestic, and also has ABS diagnostic capabilities for 1996 and newer GM, Ford and Chrsler models. The INNOVA 3150 ABS Scan Tool can display, define and troubleshoot ABS fault codes for most brake light warning systems such as: ABS Solenoids, ABS Pump Motors, Brake Switches, Control Modules, Speed Sensors and more. (Visit www.CanOBD2.com for coverage details). The scan tool plugs into the 16-pin OBD II connector, and can also be linked to a PC to record data, and for updating. The price is under $250.