PCM Reprogramming - Transmission Digest

PCM Reprogramming

Many of us can agree that the older we grow, the more quickly time passes. Manufacturers would do well if they could invent a brake that could slow the clock of life. At times this clock of life seems to be similar to that of a brakeless 18-wheeler with its trailer fully loaded, barreling downhill, delivering the uncomfortable feeling of helplessness – you know, the feeling of recognizing that this out-of-control rig has got to come to a stop somehow.

PCM Reprogramming

Technically Speaking

Author: Wayne Colonna, Technical Editor

Technically Speaking

  • Author: Wayne Colonna, Technical Editor

Many of us can agree that the older we grow, the more quickly time passes. Manufacturers would do well if they could invent a brake that could slow the clock of life. At times this clock of life seems to be similar to that of a brakeless 18-wheeler with its trailer fully loaded, barreling downhill, delivering the uncomfortable feeling of helplessness – you know, the feeling of recognizing that this out-of-control rig has got to come to a stop somehow.

A program on television that I enjoy is “Inside the Actors Studio,” hosted by James Lipton. This man interviews actors and actresses before an audience of aspiring actors, and they discuss their various acting techniques. After Lipton has completed his interview, the audience has the opportunity to ask each special guest their own questions. On one such occasion, Paul Newman was Lipton’s special guest. When it came time for the audience to ask questions, one woman stood up and asked, “Mr. Newman, with all due respect, how does it feel, after being such a success as an actor in many leading roles, that the scripts being offered to you today are for that of an older man?” After some delay, he responded, “I think Betty Grable said it best: ‘Getting old is not made for sissies.’”

It seems that it was only yesterday when we began to learn about the federally regulated OBD-II system. All car manufacturers that wanted to sell their products in the United States had to comply with this emission-control feature by the 1996 model year. If I recall correctly, Toyota was the first to comply, introducing OBD-II in some 1994 vehicles, and others followed shortly thereafter. This new system has increased the complexity of drivetrain control, but it certainly is necessary. You can appreciate this on a greater level if you have visited a city in a part of the world where there are no emission controls. The pollution is so thick your eyes become irritated, giving you a good indication as to the effect it is having on your respiratory system.

So now we are in the seventh year since the OBD-II system has been in use, and it continues rapidly changing our world. At first, we needed to get adjusted to the new code system, which, for most vehicles, requires a scan tool for retrieval. Those who dragged their feet in acquiring a scan tool began to realize that “paper clip” code retrieval was a technique on its way to extinction. Positively, this advancement elevates the technician in ability, performance, earning power and social status.

But just before this point, we faced another new concept regarding the vehicle’s computer systems –reprogramming. The Chrysler 41TE transaxle’s pinion factor came into being in 1993 when the company eliminated the distance sensor in the axle housing. If the TCM was changed, the vehicle had to be driven to the dealer to have the appropriate pinion factor flashed into the TCM. This gave the TCM the ability to calculate vehicle speed using the output-speed sensor of the gearbox, thus eliminating the need to have several different TCMs in stock to accommodate the variety of final drives and tire-size combinations. It was some time before this capability of reprogramming the pinion factor became available to the generic scan-tool manufacturers. In the meantime, technicians were forced to take vehicles back to the dealers for this service. And I can assure you, this was not a welcomed scenario for the transmission world. It was accompanied by very little in eloquent speech. Of course, the question arose, “Why can’t we do it our-selves?” And now we can.

Another example I can remember was the first time I received a call from a technician regarding a 1994 Chevrolet Caprice that wouldn’t run after he had installed a new computer. Where do you think the old one was? At the dealership that took it when he bought the new computer. He then had to have it towed to the dealer for a computer flashing to give it the data it needed to run. The technician used lengthy eloquent speech here.

The OBD-II system has come a long way in a relatively short time. Reprogramming really didn’t sneak up on us. We have had signs of its arrival. Computer reprogramming or re flashing, whichever you choose to call it, is commonplace in the automotive industry. This process is used to broaden a sensor’s window of operation instead of replacing the sensor. It is used to correct a variety of drivability complaints or false codes produced by any number of causes, including a noisy alternator. As long as it does not exceed government emissions restrictions, it gets flashed.

This explains why the bulk of factory bulletins released today cover reprogramming fixes. Consequently, the question that the aftermarket often asks is, “Why can’t we do it ourselves?” And the answer is, you can. To appreciate what this entails, we will need a little background.

There are two ways to reprogram a computer. One is called a “down-load,” and the other is called the “pass-through method.” Each method requires a scan tool, and the pass-through method additionally requires use of a personal computer (portable or stationary).

Chrysler uses the DRB III (Diagnostic Readout Box III, its scan tool) in conjunction with the MDS-2 (Modular Diagnostic System 2).

Ford uses the NGS (New Generation Star Tester, its scan tool), implementing the download method in conjunction with its Service Bay Diagnostics.

General Motors uses its Tech 2 scan tool in conjunction with the TIS (Techline Information System) for its Service Programming System (SPS).

Having these abilities in the after-market is a relatively recent development. OTC/SPX Service Solutions, Vetronix, Ease Diagnostics and Hickok are making great strides in these areas.

OTC offers equipment for both GM and Chrysler. At one time it offered the Tech 2 scan tool and SPS reprogramming. Now with its Genisys and Pathfinder 2001 MegaRelease software, SPS reprogramming is available with updates on CD. It must be used in conjunction with a dedicated desktop PC with a Pentium processor (CPU minimum requirements are 166 MHz w/MMX; RAM: 32 MB; hard drive: 2.5 GB; video RAM: 1MB; LS cache: 256 KB; CD-ROM). The Genisys GM Reprogramming Kit number is 3421-17. Visit its Web site at www.genisysotc.com.

The DART (Diagnostic and Reprogramming Tool) for Chrysler vehicles is on its way out. The new tool to replace the DART had not been announced when this article was prepared.

Vetronix, the maker of the Tech 1A and Mastertech scan tools, also offers to the aftermarket GM’s SPS reprogramming. CD updates are available from GM’s Expertech program. It, too, needs at least a 233-MHz Pentium II processor, 6 MB of free hard-drive space and 128 MB of RAM. Only Intel CPUs are recommended. Vetronix also has Service Bay Workstations available. You can visit its Web site at
www.vetronix.com/diagnostics/sps .html.

Ease Diagnostics also offers GM reprogramming only to the after-market. What separates Ease from everyone else is that you do not need a scan tool for this process. You buy from an interface hardware that connects the PC (same specs as listed with OTC) to the car. The company gets its CD updates directly from GM. It also makes it available to reprogram the computer without the computer being in the vehicle. You can visit its site at www.obd2.com/sps/data/sps.htm.

Hickok makes available to the aftermarket the NGS scan tool and the capability to reflash Ford’s EEC-V computer systems by using a PC as well, and you can see it at the Web site www.hickok-inc.com/ngs/ngs-flash.html.

So the answer is YES, the after-market can reprogram computers. It is important to note that the reprogramming is limited to what the auto manufacturers make available. You cannot do any rewriting of your own. Each of these aftermarket services offers these update programs on CDs or via modem downloads into the PC. This means if you are fighting some kind of drivability problem, you will first need to see whether an update program is available to cure the complaint. If there is a program that matches the complaint, the rewrite process requires extreme care to maintain good system voltage by using a battery booster pack and many other precautionary measures. Otherwise, permanent damage can occur to the computer being flashed, and replacement becomes necessary. One other note: Once you reprogram the computer, you cannot go back to the original program.

Is the equipment expensive? If you would like enough equipment to flash more than one automaker’s computers, the answer is yes. If you are interested in only one manufacturer, it becomes very affordable.

Is it worth the investment? Since reprogramming bulletins being produced by the Big 3 amount to nearly 50% of the volume of all their other bulletins, I would say computer reprogramming is a trend that will become increasingly more popular. It may not be very long before you find yourself at the dealer’s mercy for a reprogramming job on its timetable and at its service charge.

Reprogramming can be another avenue for you to produce revenue with very little competition at this time. Times are changing rapidly in this field, and this may be a tough choice to make. Consider this: Suppose you had a torque-converter-clutch shuttle caused by a glitch in a throttle-position sensor (TPS). You could either change the TPS or flash the computer to fix the problem and get paid for your expertise. This is inviting, especially so since we know that new does not mean good. If you have a bad TPS, you can replace it with a new one out of the box and it can be as bad as or worse than the one replaced.

Time waits for no one, and times are moving swiftly. When it comes to the automotive field, growing with the times is not made for sissies.

Oh, by the way, I didn’t have time to talk about HYPER TECH. It has Power Programmers that are vehicle specific, offering many features such as speedometer/odometer correction that automatically corrects speedometer and odometer readings with non-stock tire sizes and/or non-stock differential gear ratios. You can have fun at its Web site at
www.hypertech-in.com/programmer.html.

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