Smart Engines Require Smart Programming

If you run late-model tractors and trucks, chances are your diesels are electronically controlled. That means you have a great deal of flexibility over how those powerplants perform as they run up and down the highway. And who couldn’t use more flexibility?

Trouble is, with control comes an added degree of complexity.

There are about 60 parameters-each defining a range of operating characteristics-in the controls of a typical engine. How do you set the parameters in the “black box” and how do you keep them from being tampered with?

It’s a daunting subject, one worth asking your engine rep about. Not minding this aspect of modern technology can cost you money in fuel and other operating areas. Here are some key areas to consider.

PASSWORDS

These are secret numbers programmed in like padlocks to keep out anybody who’s not authorized. Before a technician goes into the box to check or change its programming, he must first enter the password (unless none was installed, which you may prefer). You can make up a password for each truck, or one for each group of trucks, or the same one for every truck in the fleet.

With some engines, the driver can enter a password on top of the fleet’s password. This can be an effective anti-theft device because it keeps someone else from starting the engine or running the truck too far.

But if you let the driver do set a personal password, be sure he tells you what the personal password is in case (God forbid) he dies suddenly or quits in a huff and leaves the truck inoperable. (Hey, it happens.)

The primary concern among fleet managers is protecting their passwords. Because reprogramming isn’t done too often, you may not want your technicians to have them (you or the foreman can punch it in when necessary).

In most cases, drivers probably shouldn’t have the password, either, unless you trust them to not use it to let a friendly tech “hop up” the engine.

Engine-makers do offer programs that are designed to prevent tampering. These automatically revert the controls to preset limits if someone tries to reset them.

One fleet set up its controls with a fusible link that would blow if anyone tried to tamper with the controls. This would disable the engine, and the truck would be stuck right where it was when the phantom tech tried to do his dastardly deed.

PARAMETERS

Setting parameters in the first place is done at the truck builder’s factory. If the build sheet is filled out completely, the technicians will know precisely which numbers they’re supposed to punch in. But they don’t always have complete information.

Perhaps you or the salesperson at the dealer didn’t specify everything, or the specs weren’t communicated to the factory. So, often the factory tech will punch in an established set of parameters that will work pretty well for your engine and driveline in your given application.

Otherwise, a “default” set of parameters may be used.

In either case, you’re not getting what you spec’d. For instance, you may want to control revs in each gear to force drivers to shift progressively (at lower revs in lower gears).

But if this isn’t specified in the sheet, it won’t be done and the engine will be allowed to rev to its standard redline (1800 or 2100 rpm) in every gear.

That may be just fine with you because you know that sometimes they have to rev higher to catch the next gear (as while climbing a freeway on-ramp).

But if you want progressive shifting limits programmed in and it’s not done at the factory, you won’t get it. You’ll have to take the truck off the road and pull it into your dealer’s shop so the engine can be programmed the way you wanted it set in the first place.

Among other key parameters is pulses per mile (pulses are generated by a magnetic pickup somewhere on the vehicle) which, along with axle ratio and tire size, determine the allowable road speed and cruise speed. (For instance, knowing that tread wear slows down the truck at the rate of about 0.1 mph per 1/32-inch of wear, you’ll be better able to exam wear-rate patterns on your vehicles.

Another thing to check frequently (at PM intervals, for instance) is when the parameters were last set; anything not recorded in your own records may be an incident of tampering.

This parameter and all the others that can help you control how the vehicle is driven (here you and your drivers can resume your ongoing debate on road speed limits) will help you and your drivers get the most out of the engines.

By “most” we’re talking about performance, fuel economy, and durability. You as the fleet manager should decide the parameters, preferably after consulting with drivers. It’s safe to say they’ll appreciate you for it.

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SIDEBAR: GOOD ADVICE

Before you pick up your truck, make sure you’re getting what you ordered (and paid for). Ask whether your engine parameters have been set (your dealer should have done this for you). Setting your parameters later is just another pain in the neck, and you may have to pay extra for it. Then, make sure they’re set properly. Sometimes, in the crush of business, settings may get overlooked and you may find the truck doing things you never asked for. These will show up as you gather trip data. (You do look at these, right?)