March
2011
"STORIES"

It's been 19 years since the first computer controlled electronic diesel engine for semi trucks has been released. These days everything on the engine is monitored and controlled by the engine computer, also commonly referred to as the ECU (Electronic Control Unit) or ECM (Electronic Control Module). Each year electronic systems in trucks become more and more integrated in the truck. Just being good with a wrench doesn’t cut it anymore. Technicians need to truly understand the electronics and the ECM.

Think of your trucks ECM and its electrical system being similar in function to your body's electrochemical nervous system. The ECM is the brain and can "feel" problems though its wires and nerve like sensors. If sensors are the ECM's nerves then solenoids (including injector solenoids) can be thought of as the ECM's "muscles" that the ECM has control of. Sensors are designed to produce a specific range of either electrical resistance or voltage that changes with temperature, pressure or in the presence of an electromagnetic field.  Each sensor typically makes a single signal circuit that feeds into a pin on the ECM. The ECM powers the sensor though a sensor supply and sometimes a sensor return circuit, then monitors the sensor signal wire by watching the voltage range the sensor sends back. If the voltage drops too low or goes too high the ECM will let you know by turning on the check engine light. The ECM will tell you where to look by giving you a code that identifies a specific circuit and condition. Your brain does this as well and will quickly let you know if you're touching something that's outside of your comfort range whether it's a little snow that falls on your arm or when you’re getting into your truck and bump into one of your stacks.

Compared to your nervous system an ECM is very dumb. Most ECMs have no way to verify what the truck is actually doing. The ECM is simply reading a voltage and making an assumption. Because of this ECMs are easily fooled. I had a DDECV ECM tell me it was reading a turbo compressor outlet temperature of 1600 degrees. This was while the truck was at idle! Remember that the ECM is just a machine. It doesn't know the temperature was actually 1600 degrees. The ECM was only going by what voltage it received from what it thinks was its temperature sensor circuit.  When ECMs do crazy things like read 1600 degrees at idle don't assume the ECM is bad. There is a big difference between an ECM that is bad and an ECM that is simply being fooled. The ECM that is being fooled is doing its job correctly.  What is not working correctly in this case is the electrical circuit or sensor the ECM is monitoring.

Among technicians in the trucking industry the most widely misunderstood part of the truck is the ECM. As a result the ECM has become a scapegoat for almost any problem the technician fails to identify. A mechanical problem that a technician fails to recognize or recognizes but fails to fix properly is often blamed on the ECM. I have had people blame the ECM for everything from bad valve timing to CB radio interference. Here is a hint. If there isn't an electrical solenoid or sensor involved with the system having the problem, then the ECM has no control over that system and you're barking up the wrong tree.

From time to time ECMs do fail. ECMs have a limited lifespan.  All ECMs have some sort of flash memory. Over many years this memory will deteriorate and ECM related circuits on the truck will fail. Also some ECMs rely on a battery that powers the memory chip and when the battery wears out your ECM will soon fail. Sometimes you will get a check engine light, sometimes you won't. The ECM will almost never leave you stranded though. You will have a warning, and several days driving time left to get to a shop.  Now these batteries usually last about 10 to 12 years and then the ECM needs to be replaced.  We recently had a 2005 Caterpillar Acert in the shop and the ECM had failed so occasionally they will fail before their time. This ECM was only 6 years old and needed replaced.   Having us reprogram an ECM that is about to fail or has other hardware problems is not the answer.  These problems are not repairable and reprogramming will not fix these problems.  Yes we can give it more horsepower, however if the ECM is ready to fail or has other problems, turning up the power will do nothing to fix or extend the life of the ECM.

In the trucking industry technicians tend to take shortcuts when working on electrical problems. Instead of tracking down the source of the problem these guys start making assumptions and changing parts. It doesn't matter whether the technician doesn't understand how to diagnose an electrical problem or is just too lazy.  You’re the one who's buying the parts so their assumptions end up costing you. These guys will typically tell you that the ECM, a sensor, a wiring harness or even an injector is faulty without bothering to test the part and verify that it has failed. These parts are expensive and the technician telling you to replace these parts isn’t buying them. You are.  So beware of any technician that doesn’t have a well-used multi meter sitting in his toolbox.

Electrical problems are not always easy to find especially if they are intermittent. Some problems only show symptoms under load, some only at a specific rpm, others only when it's cold outside.  Most intermittent electrical problems come and go with no observable reason at all. Thankfully if your ECM does produce a check engine light that will log which circuit produced the problem. If a wire is severed or a sensor fails, the ECM only knows it's getting zero volts back from the sensor.

 You may just have a dirty, loose, corroded, wet or filled with oil connector. To find out you have to ohm out the circuit to find the break with a good old-fashioned multi meter. Diagnostic software won't do this for you. Your multi meter is the only way to be sure.

The relative simplicity of our Pittsburgh Power Computer allows us to diagnose those problems over the phone but that is where it stops.  These problems are very difficult to find unless you have good diagnostic software and a multi meter. We get many phone calls about electrical problems and we will not attempt to diagnose an electrical problem over the phone. Phone calls like this only make both of us frustrated. You must take your truck to a good truck shop that is competent with electronics.  When you call us with these wiring problems we will tell you to make an appointment. Please don't say, "I don't run to the East or the North East." If that is the case then we can't help you. You are going to need to find a shop that is good with electronics. 

Return authorization numbers or order numbers:  Sure…they might seem like a hassle. We can see your side of it. You probably just got off the phone with Pete about sending your injectors in to be recalibrated and you pack them in a box and send them to our shop. You happen to forget the order ID number but you just talked to Pete and he will remember you so it's ok. Now let me show you our side of it.

Pete talked to three different guys today about getting their injectors recalibrated and you were one of them. He also sold 7 sets of injectors last week and is expecting cores for all 7 sets to be sent in. Then the UPS or FED-Ex driver brings 30 boxes to our place of business.  The shipper now has to determine what and where the boxes go.  The first thing he does is look for order ID numbers on these boxes. The boxes that are unidentified get opened up and this is when he finds your set of injectors.  Unmarked and unidentified he automatically thinks these injectors are cores being returned because otherwise there would be an order ID number on them. Off to the rebuild shop the injectors go or to the core bank at Cummins, Cat or Detroit, never to be found again.  Then a week later you give us a call and you ask if we ever got the injectors you sent to be recalibrated?  We say, "What injectors?" And now the confusion starts.  If you don't put an order number on the outside of the box, a short letter on the inside with your name, address, phone number and what you need done with the parts they just might end up in the core bin.  Please call and get an order number for anything you want to return to us so the confusion can be halted.

 Demand is higher than ever for glider kits. There is currently a four month wait for the delivery of 2012 Peterbilt glider kits from Peterbilt. If you need a 2012 custom Peterbilt glider you need to plan at least 6 months in advance. If you procrastinate too much you'll be waiting til next year.  Guys calling us today that are going to need a truck in two months are out of luck and are now faced with buying a new emissions truck or buying something used and having us upgrade it to glider like specifications.  Another thing to plan for is the cost.  Some clients are shocked at the total cost of building one of these custom trucks. The dream of having the ultimate truck that will outperform a stock factory truck by 1 to 2 mpg is an expensive one.  The cost of the glider kit can range anywhere from $80,000 to $120,000 and this is about half the cost of completing the truck. It’s almost hard to believe that a "kit" would need so many extra parts to finish the job. For example, you still need the bell housing, the flywheel, the pilot bearing, the fan hub, the alternator, starter, front engine mount and bolts, rear engine mounts and bolts, solenoid switches, block heater, alternator pulley, 3 or 4 batteries, battery cables and ends, coolant pipes, air piping, all the clamps, all the hoses, the fan blade, the valves, lots of loom and clamps, an engine wiring harness, Fass Fuel System, OPS-1 bypass oil filter, Pittsburgh Power Computer, 5 inch exhaust system, mufflers and clamps, the chrome elbows, 7 inch chrome stacks, the Horton fan switch, antifreeze, R134-A refrigerant, engine oil and filters, transmission, synthetic transmission fluid, the Lipe clutch, clutch kit shafts and yoke, clutch linkage, heat exchangers and hoses, driveshaft, shifter, shifter knob, clutch brake, engine sensors, and of course the engine.  All those parts add up let me tell you! Then we have to make our own OEM side wiring harness and program the computers to make the engine talk to the instrument panel and the computer in the truck. It's not just plug in the harness and hit the key.  Now to put all those parts on this truck takes our team 200 hours of labor or more.  We had to assemble a team of technicians with a very diversified skill set to accomplish this feat. So please don't think that all you do to finish a glider kit is install and engine and transmission. As you can see there is a little more too it then that.

If you haven't read many of my old articles and have just started hearing about gliders your probably wondering why anyone would want to pay anywhere from one hundred and eighty thousand to two hundred thousand dollars for a glider truck when a new emissions truck can be bought for less money. It all boils down to operating cost and downtime.  Let's look at what you would save per year with a custom glider kit powered by a custom Pittsburgh Power built engine. 

These figures are based on 150,000 per year and a fuel cost of $3.40 per gallon.

 No EGR-DPF-Urea engines failures, plus $12,000

At 1 mpg fuel savings over the factory truck; $14,266    
 Total savings per year  $26,266

At 2 mpg savings over a stock factory truck; $24,727

EGR failures and downtime; $12,000

Total savings per year $36,727

If you're a team operation and run 280,000 per year like some of our Fed-Ex guys do the fuel savings alone total out to be $46,157 per year.

Do the math, just think if you're now getting 5 mpg and we can get you up to 8 mpg what you would save.  Some tell us we are being too conservative with our operating cost figures for EGR-DPF-Urea engines. Ask some of the owner-operators that have them, they will tell you it's closer to $18,000 per year. We are being conservative at $12,000 per year.  Another item I forgot to mention about the hand built Peterbilt Glider Kit is the performance, yes you will not have to worry about running out of power, you will have more power under your foot than you will ever need.

Written by Bruce Mallinson; Edited by Fernando DeMoura; Pittsburgh Power Inc.; 3600 S. Noah Dr. Saxonburg, Pa. 16056. Phone 724-360-4080. Email: bruce@pittsburghower.com or fernando@pittsburghpower.com