ABS Troubleshooting: Is There Still A Problem?

Why are technicians still misdiagnosing ABS?

"I think PC-based software is the wave of the future," echoes MeritorWABCO's Williams. "There's more capability for wireless interfacing and things like that, so I definitely think that PC-based diagnostics is the way to go.

"We don't provide our own PC-based software," he adds, "but it is available through a vendor (MeritorWABCO TOOLBOX software from SPX). There are a couple of manufacturers out there that have a wi-fi system, so you have a laptop and a diagnostic interface plugged into the port, and they can literally walk around the truck with that laptop, and still communicate wirelessly through that diagnostic interface."

"You're going to need a computer with software to be able to get in and troubleshoot and diagnose systems correctly," says Bendix's Reid. "We have what we call a Remote Diagnostic Unit (RDU), which is a little unit that plugs into the diagnostic connector of the vehicle, and LEDs light up to tell you where the faults are. It gives you a general idea where the fault is. It doesn't really dig down and tell you whether you would have a shorted wheel speed sensor, or an open wheel speed sensor; it just tells you there's an issue with the wheel speed sensor.

"When you get into PC diagnostics, you could actually diagnose that, yes, the wheel speed sensor is open, or shorted," he explains. "Or you could connect your PC to the vehicle and drive down the road and actually look at the wheel speed signals and see what they look like."


"All the ABS suppliers do a good job of providing information," says Weed. "There are 1-800 numbers, there's maintenance information out there over the internet. I know Bendix offers a very good air brake school. I would certainly encourage fleets to take advantage of that.

"I would also emphasize the requirement for technicians to follow a very disciplined, very methodical approach to troubleshooting an ABS system," he says, "and not just automatically start replacing components."

"I think fleets are going to have to invest in their technicians and send them to training," Reid says. "As systems become more complex, the technicians are going to have to diagnose problems and not just change parts. I just had a situation the other day where the technician had changed three electronic controllers and hadn't done anything else. That becomes very expensive to the fleet."

For dates and locations of Bendix Air Brake and Foundation Brake Training and MeritorWABCO Stability Control Demos, see the Brake Supplement.

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