Today's Trucking
products Engines/Drivetrains Other


Posted: August 1, 2014 by Jim Park

The modern ECM is a lot more than an injection timing device.

You’re paying for a lot more than nuts and bolts when you buy an engine these days. But many owner-operators may not be taking full advantage of the product they’re stuffing under their hoods.

Why settle for an off-the-shelf engine when you can customize the operating parameters to suit your application? Want the engine brake to kick in on only two cylinders at 10 km/h over the pre-set cruise speed? No problem. It’s just a matter of telling the dealer to make the engine do what you want it to do.

But first you need to know what you want, and unless you’re in the habit of digesting dozens of product manuals from the manufacturers, you might not know what’s available. That, frankly, is the salesperson’s job, but you should be aware that the engine control module (ECM) is now much more than just an injection-timing device.

Erin Toth, sales manager at Regina Freightliner, says his fleet customers come in with a long list of parameters they’d like programmed into their engines, but he sees few owner-ops doing the same. A fleet might program for efficiency or cost control, but there’s a multitude of other operating parameters that could benefit the owner-operator as well.

“On our Century Class trucks, for example, you can program the engine to disable the cruise control while the windshield wipers are in use,” Toth says. “That assumes that the roads are wet and potentially slippery, so we offer the feature to provide an extra margin of safety.”

That’s just the beginning. If, for example, you plan to operate a power takeoff (PTO) device such as a wet line or a liquid product pump, you can program a limit to the engine’s available torque output while in PTO mode in order to prevent damage to it. If the torque-limit parameter isn’t pre-set by the customer, the engine may just start cranking out the pound feet until something expensive breaks under the strain.

The pre-setting of personal operating parameters is normally done at the point of sale — when the truck is ordered — as some settings are databook options programmed at the factory. It’s always a good idea to have the shop manager hook up his Pro-Link tool to the truck when it’s delivered to ensure that all your custom-spec’d parameters are in place. Assume nothing here.

Trimming Costs

Most fleets set a lot of their own operating parameters, and for one good reason: to reduce costs. Limiting the vehicle or engine speed is intended to lower fuel consumption by removing the driver from that particular decision-making loop. But you own the truck, so why shouldn’t you drive it the way you want to?

The same logic the fleets use can certainly be applied to a small business operator as well. Any benefit you can gain from operating your equipment more efficiently will be to your advantage — even if it means surrendering a small degree of control to a higher power. If personal discipline is a problem, reprogramming your engine can help.

You may also want to pre-set some high-engine-speed limits for each gear to encourage more efficient driving through progressive shifting. Once you’ve proven to yourself what a difference it can make, maybe you can undo that particular setting and take all the credit yourself.

Idle timers and self-shutdown features allow you to walk away from the truck as soon as the parking brakes are applied rather than waiting for the obligatory three-minute cooldown. Some engine makers are now offering a temperature-sensitive engine start-up feature designed to allow the engine to cycle on and off while the driver sleeps to maintain a comfortable interior environment. You may also pre-set the engine to cycle on and off during periods of extreme cold so that it never gets too cold to restart, or it can sense a dying battery and restart the engine before all the juice is lost.

The ECM can also be custom-programmed to select the level of self-protection desired in the event of several different abnormal conditions. Oil pressure, coolant temperature, coolant level or high intake-manifold temperature are just some of the parameters that can be selected, and each can be set to respond in different ways – anywhere from a warning, to a progressive de-rate of engine output, to outright shutdown.

The default settings programmed at the factory may not be the best option for a particular application. Take the engine brake’s low-speed cut-off, for example. If the default shut-off point is 30 km/h and you haul out of a gravel pit where long steep descents are part of the job, you may want to reprogram that setting to a lower speed, say 10 km/h, in order to creep down the hill.

If you find the engine fan comes on when using the Jake, you can change the default setting to fan-off instead of fan-on. You can modify the way the Jake engages as well, from full manual to auto-on without touching the brake pedal, or only after touching the brake pedal. Cruise control, sensiby, can be programmed to give you a couple of klicks grace on either side of the pre-set cruise speed so that it isn’t cycling to full throttle at the slightest hint of a hill or zero throttle on a slight downgrade. This provides a smoother ride and more fuel-efficient throttling, in much the same way a skilled driver eases up or down on the pedal in response to changing terrain.

Don’t forget that almost all of these various engine parameters can be programmed at any time, not just when you order the truck. So if you bought your rig a couple of years back and didn’t realize how much could be programmed, don’t despair. It will cost you a dollar or two to have your local engine distributor dive inside that ECM, but not outrageous amounts, and it’s likely to be money very well spent.

The same holds if you bought a used truck. In that case, chances are good that you have no idea how the engine was originally spec’d, so you’d be well advised to find out. It’s an easy task to pull out the programmed parameters and then decide which you’d like to change. You might even want to change power.

That’s the killer programming possibility, and it could mean a lot at trade-in time. If you originally bought a 400-horse engine but now find that most people want a 460, head for the engine shop and have it uprated. You can’t turn that 400 into a 600, nor a 300 into a 460, but within certain ‘iron’ families – that is, engine ratings that use the same turbo, injectors, and the like – you’ve got tons of flexibility. Uprate your engine and you may sell the truck more easily, or maybe even get a better buck for it.

Whether you’re selling or buying or just improving, it’s almost certain that a personalized spec will be more to your taste and will suit your application more precisely than the off-the-shelf factory settings. The software is already built in. All you have to do is ask.


  • This field is for validation purposes and should be left unchanged.
Related Articles