Technology Today: The Noise of Fault Codes

By Pat Crail, CEM, Contributing Editor | August 30, 2011

One of the exciting promises of telematics is the ability for machines to self-report problems, alerting fleet managers to impending failures or improper operating techniques through automated notifications. A recent AEMP survey of telematics users revealed that fleet managers highly value fault code alerts. For all its promise, however, this particular feature of telematics systems can be a source of tremendous aggravation.

The challenge is in deciding which fault messages require action and which are just noise. I have our accounts for each manufacturer set to alert me to only the most critical fault codes. In the past two years, I have accumulated more than 4,000 fault messages from a group of approximately 35 machines. That’s roughly one alert per machine per week. Of those thousands of alerts, only four have been actionable. Three indicated air filter restrictions, all of which were failed sensors rather than actual restrictions. The fourth alert was for an overheating machine, but by the time that I received the alert, the operator had shut the machine down and called the shop to report the problem.

The electronic control modules (ECM) on today’s machines can monitor a multitude of circuits controlling everything from fuel-injection systems to implement-control systems. If the value on a given circuit falls outside of its programmed parameters, the ECM interprets this as a problem, stores a fault code, and in many cases, sends an alert through the telematics system’s interface. In theory, the fault code indicates a problem that requires action.

In reality, however, a number of situations will cause a circuit’s value to fall outside of its expected range, thereby generating a fault code. Some situations indicate a true problem, while others are merely due to a particular operating condition that the engineers did not anticipate when defining “normal” parameters.

For example, a motor grader with electrically controlled steering can generate a fault message if the ECM senses that the steering axle’s wheels are turning without a command from the operator. This could indicate a malfunction that is causing a loss of steering control. However, this fault could also indicate that the machine is operating in muddy conditions and the resulting rutting is causing the steering wheels to turn slightly without operator input. In that case, such movement is a normal consequence of the operating conditions and requires no action. The resultant fault message becomes one more piece of noise in our already busy day. As technicians are well aware, the ECM merely records the fault code. It is up to us to determine whether action is required.

Technicians have dealt with this problem for years, but telematics systems have made these fault codes instantly available to a wider audience. Now fleet managers can opt to receive text or email messages every time a machine generates a fault code. Those unfamiliar with ECMs understandably assume that each fault code alert indicates a problem. Eventually, after trying to take action on each alert, they discover that many machines generate fault codes during normal operation.

Until the technology evolves to better identify the truly actionable alerts, I can do without them. In the case of potentially catastrophic conditions, the flashing lights and buzzers in the cab are sufficient to alert the operator to shut the machine down and call the shop. However, as the AEMP survey indicates, many fleet managers disagree.

So if you want fault code alerts, how do you cut through the noise? Start by working with your telematics providers to filter messages to only the most critical alerts. Don’t have alerts sent to your entire management team; designate one recipient to review the alerts. Work with your dealers to help you learn to recognize alerts that require action. If an alert may require action, ask the operator if the machine exhibits any symptoms. Finally, investigate repetitive reports of the same fault to spot any trends that may indicate a developing problem. A reasonable review process can provide value from this evolving technology.