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A bright idea from Europe

My feelings on the emission control systems on heavy trucks are no secret: I’m not a fan. Now don’t get me wrong, the theory behind them is good. We all want to breathe cleaner air, especially those of us who spend all day sitting...


My feelings on the emission control systems on heavy trucks are no secret: I’m not a fan. Now don’t get me wrong, the theory behind them is good. We all want to breathe cleaner air, especially those of us who spend all day sitting behind a diesel engine, as we have the most to gain from taming the emissions.

It is the execution that I have the problem with. The reliability of a truck has suffered as a result; for the most part it isn’t the mechanics of the systems that cause the problems, but the electronics. Almost every time that little yellow light flashes up on the dash, it isn’t a hardware issue. The nuts and bolts don’t break; it’s almost always a glitch in a sensor or relay.

I have read some research by a well-respected engine shop that suggests a lot of the issues come about as a result of a drop in voltage; even 11.99 volts can trip out a sensor. So even the tiniest drop in supply can trigger a check engine light that will stay lit until you visit the dealership to get the fault cleared.

The visit to the dealership will be inconvenient in itself, but sometimes the truck will de-rate and you may need a service call to a truck stop, or more likely, the side of the road in the middle of nowhere.

A statement I hear quite often, and one I’m guilty of using myself, is that technicians nowadays are little more than parts-changers that would be lost without their laptop. This is true to a degree, but it is more an indication of the problems that they are trying to fix, rather than their lack of ability.

Today’s trucks don’t need metal parts replacing or fixing, they don’t wear out like they used to and a big reason for that is electronics, so although the check engine light has become a thing we see far too often, the fact the our truck has one likely means we don’t have catastrophic failures of major components anymore. So although that little yellow light is a pain in the you-know-where, it also means that your engine is protected against major failure.

Obviously the downside is that the little things in the electrical system are, to put it kindly, temperamental at times. This doesn’t seem to be so much of a problem in Europe. Sure, they have issues of their own over there, but the frequency of failure is far less than we experience over here.

So why is that? The DD range of engines from Daimler, in Freightliner and Western Star, the MX series of engines from Paccar in Kenworth and Peterbilt and lastly the Volvo engines in Volvos and their Mack derivatives in Mack trucks are all ‘world’ engines. Only a few emissions-related differences separate them from their European cousins.

The only difference I can see is that the electrical systems on European trucks are 24-volt. Is this the thing that makes their electrical systems so much more reliable? Are the fluctuations in voltage minimized by increasing it? Not only that, but why do the manufacturers go to all the trouble of designing different systems for a world engine? Surely a commonality of parts would not only bring down production costs, it would also put more of the same product out there and make ironing out the bugs a far quicker process.

I know that emissions regulations are different around the world, but we are reaching a point where everyone is targeting the same things; most of the nasty stuff that exits a tailpipe has been eradicated on both sides of the Atlantic. Both continents are using the same alphabet soup of EGR, DPF and SCR to control emissions, so why are the manufacturers struggling with the EPA regulations more than their engines struggle with the respective Euro emissions controls?

Could it really be something as simple as a lack of voltage? Surely the vehicle light bulb industry doesn’t have enough power to prevent the adoption of 24-volt electronics throughout the world. After all, that’s the only thing that would need to be changed to switch over to 24 volts on North American trucks.

The short answer to all of that is no, if a sensor is so susceptible to a micro-drop in voltage, it will trip out no matter what voltage it runs at, but I see a simple solution to that problem and you won’t need to swap out all your light bulbs to make it work.

If all these sensors need a constant amount of current passing through them to ensure their reliability, how about making them six or 10, or even 11 volts, put a rheostat or something clever inline to ensure that the 12 volts – or sometime less – fed into the engine’s electrical system can always supply a constant voltage to the parts that rely on it so much?

Maybe then that little yellow light will only appear in emergencies Technicians can get back to fixing stuff using the contents of their hard-earned toolboxes, dispatchers and fleet owners can take breakdown assist off their speed dials and drivers can fire up their truck at the start of their shift, confident that they will spend the day putting miles under the bumper and not sitting on the shoulder with their head in their hands.


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