Underhood Service Advertise | Subscribe | Contact Us | About Us
Twitter
Facebook
autoprojobs.com

Flash! Reprogramming Vehicle Computers

December 1, 2004

Typically, when someone brings up the subject of “flashing” you get two reactions. The technologically informed service professionals think about added revenue and service, while rowdier folks think about doing something that could land them in front of a judge.

I think we can all agree that the first group is far better off, and the only thing we need to expose is the benefits of this new “flashing” technology. In case you’re on the technological slow boat, “flashing” refers to reprogramming automotive engine control modules (ECMs). Before we get into what it takes to flash ECMs, let’s take a closer look at what flashing really is, why it is utilized on virtually all late-model cars and why this is such a great opportunity for repair shops.

Going back to the basics, you know that all automotive engine and powertrain control modules (PCMs) are essentially small-sized, dedicated computers. They have a microprocessor, built-in random access memory (RAM), signal-conditioning chips (for sensor inputs), output transistor/drivers (for actuating ignition coils and fuel injectors) and a programmable read-only memory-type chip (PROM) for calibration purposes. Naturally, this short list does not describe the entire contents of the ECM, but what is important to our understanding of flashing is the PROM part of the ECM. The PROM chip is used to calibrate the ECM so that it is configured to run a particular engine. For example, in 1989, Chevrolet used one engine control module, P/N 1227165, to control three different engines. This ECM was used on the 1989 S-10 truck with the 2.5L four cylinder, the ’89 Camaro with the 5.0L HO V8 and the ’89 Corvette with the 5.7L Tuned-Port V8 engine. The only difference (aside from the vehicle wiring harness pin population) was the PROM. The PROM contains the calibration software for the ECM. To clarify this a little further, let’s take a look at the software structure within the ECM.

When you first turn on the ignition switch in the car, the ECM goes through a power-up mode not unlike your desktop PC. The ECM’s microprocessor has embedded software that instructs the microprocessor on its initial tasks. One of these tasks is reading the PROM. The software contains the instructions on how to control an engine or powertrain. Using this software, the ECM will know how to initiate ignition primary dwell and actuate spark output, as well as how to actuate the fuel injectors, how to control the EGR valve, etc. What it does not know is the quantities: how much spark advance, how much fuel to inject, how much exhaust gas recirculation, etc.

This is where the PROM comes in. The PROM is used to calibrate the ECM. By changing the PROM, we can make the same computer properly control different engines. These engines may be similar in architecture (like the Camaro 5.0L HO and Corvette 5.7L TPI, both V8s) but different in specification (different camshaft lift/duration, different EGR valves/ports, different fuel injector sizes and flow rates, etc.), or the engines may be of different architecture, like the four-cylinder in the 2.5L S-10. The software calibration within the PROM provides the proper “tuning” for the engine.

History Behind PROMs
PROMs come in many shapes and sizes. The older PROMs were only programmable once. After the PROM was programmed with a certain calibration, that was it - you couldn’t change the software anymore. If you wanted a different calibration or an update to address a TSB, you were forced to buy a new PROM and install it in the ECM. With newer technology came the EPROM, or erasable programmable read-only memory. These EPROMs were a step up, but the erasing of the software on the EPROM required that it be removed from the ECM and placed under an intense ultraviolet light source, then reprogrammed using a special programming system. The next step in technology was the electrically erasable programmable read-only memory (EEPROM).

EEPROMs were used in some early ’90s Geo products, as well as some early ’90s Cavaliers, Corsicas and Berettas. Using the TECH I, GM’s OE scan tool, a technician could recalibrate the ECM by reprogramming the EEPROM without removing it from the vehicle. The scan tool would hook up to the diagnostic port of the car, electrically erase the EEPROM and then reprogram it with the new software calibration. This process was much quicker and simpler than removing the ECM from the vehicle, opening it up, removing the PROM, obtaining the PROM ID number, ordering the part and installing everything in the opposite order of disassembly. With the new electrically erasable and programmable repair method, a great many potential points of failure and error were eliminated. Flashing was the next step.

Flashing
The main difference between flash-PROMs versus EEPROMs is the data storage capability of each, as well as the speed and accuracy of programming. It is not uncommon to see flash-PROMS in the 512 kilobytes to 2 megabyte range, whereas EEPROMs typically don’t get much bigger than 512 Kb in the automotive computer.

Regarding programming speed, flash technology allows the entire programming of the flash-PROM to be erased all at once and then reprogrammed the same way. The entire page is deleted and reprogrammed all in one continuous step, and that means that one more potential source of error is eliminated in the process. During the flash reprogramming process, all of the input data to the flash-PROM is verified to ensure accuracy.

With the older-style PROMS, carrying stock was not an option for parts stores as there were too many part numbers. A 1990 Chevy Lumina with a 3.1L V6 has at least 28 different PROMs. Imagine trying to stock PROMs for all makes and models. For this reason alone, PROMs were never big sellers, despite calls for new updates in TSBs. Technicians would rarely special-order a PROM for a TSB update, for if the replacement PROM didn’t fix the problem, the customer was either stuck with the bill for the part (including freight charges) or faced a tough return policy. Another reason for slow PROM sales was the overall simplicity of diagnostic routines in these older pre-OBD II ECMs. Fewer diagnostic routines made for more reliable software code and fewer false-DTCs or driveability problems. With the advent of OBD II and all of the software for diagnostic monitors, the size of vehicle calibration files jumped enormously, and so has their complexity and potential for problems. Addressing software-related TSBs is now commonplace and should be considered standard routine by any competent technician.

Sales Opportunities
This creates an incredible selling opportunity, and an important part of this positioning and opportunity is the potential for suggestion.

Every customer with an OBD II GM vehicle is a potential sale. Whenever a customer’s vehicle needs a serpentine belt for a ’98 Lesabre, or you need brake pads and rotors for a ’96 Grand Am, you’ll know that these are potential flash programming customers. It takes very little effort to ask a customer if they have ever had a software update performed and to suggest that you perform this service for them. Just think about McDonald’s: “Would you like fries with that?” How much of an increase in revenue do you think was generated by using that suggestion with every customer in the first year alone? What about over five or 10 years?

Almost all new vehicles today are now flash programmable. This means that somebody will need to perform the work of programming the ECM. You’d rather not have the OE dealership do the work, for if nothing else, this is an extra step in the repair process.

You’ll need extra equipment over and above the scan tool to perform flash updates. Since the return on investment may take a while, some shops aren’t jumping to buy the equipment, but there is money to be made here.

As an added sales incentive, there’s the aspect of speed of delivery. If your shop is equipped to flash program, you don’t need to special order updates or the corresponding computers anymore (remember our ’90 Lumina V6 with its 28 PROMs?) Now you can stock the equivalent of every flash-PROM calibration part number on one disc. No waiting for special orders and no fighting return policies or freight charges.

Also, don’t forget the McDonald’s example. You can only gain by asking if an update has ever been performed. If you don’t ask or suggest, you may lose out on a sale, and your customer may miss out on a valuable service.

The ECM is an important part of this equation as well. Without the ability to flash program, you are forced to rely on your supplier for inventory. Without the ability to flash, carrying high-moving ECM part numbers is not an option unless you want to tell the customer to go to the dealer for programming. With flash capability, the ECM inventory is handled like any other part - stock the high movers and special order the slow ones. With the ability to flash program, you can earn higher margins on the special order ECMs as it will be your shop that does the flashing, not the remanufacturer. Remember that every customer with an OBD II GM vehicle is a potential sale, as well as some GM vehicles manufactured prior to 1996. Flash programming was started on certain GM models as early as 1993. Once 1996 rolled around (along with OBD II), all GM vehicles had it. (See the charts below for GM flash applications.) Based on the average price of most flashing equipment on the market, if all you did was sell one flash programming service per week, you would pay the equipment off in less than one year. Market this service effectively, and you’d make the equipment costs back in less than two months.

Armed and Ready to Battle for Business
To perform flash programming, some specialized equipment is needed. A typical flash programming system consists of a desktop PC, an automotive scan tool, an off-board programming power supply, a cable/harness set and the calibration software on CD. The whole assembly takes up about 3 square feet of desk space in your shop.

There is freedom of choice in the purchase of this system, as there are a number of suppliers that are willing to sell you this equipment. Purchase price should not be the only deciding factor you go by, though. Remember that as with anything technical, you want great customer service and even better product support from whomever you choose to do business with. Regarding the operation of the system, your staff should become quite proficient in the operations of flash programming with only one hour’s worth of dedicated training. The software is reliable and is actually licensed for use from the OEMs. Basically, you will now have access to the same programming capabilities with ECMs that the OE dealerships have along with the major advantage over the dealer in that you won’t need the car to perform the programming (most dealerships cannot perform off-vehicle programming).

Armed with this equipment, you would be well positioned to supply your customers with all of their programming needs. Considering the current rates charged to customers by the OE dealers for flashing ECMs, this would also be a profitable service to provide. Charges for flashing are typically in the area of $80 to $120, and are based on the dealer’s method of programming. Since very few dealers can perform off-board (or off-vehicle) flashing, their rates are based on the time it takes for the technician to bring the car into the bay, establish communication with the scan tool and read the current calibration, perform the flash procedure, then verify the procedure once completed and return the car to the lot. This is approximately 30-50 minutes worth of work. You should be able to model your prices comparable to the dealership. But understand that doing your own flash reprogramming is not without risk. However, for some shops it may be a more practical and profitable alternative to sending vehicles back to the dealer every time a PC needs to be updated or replaced.

The advantage for your shop is that a dealer may not suggest this service to every customer as their method of programming forces them to tie up a bay. That means more market share for you.

The How-Tos of Flash Programming
The procedure for flash programming an ECM is actually quite simple due to the user-friendliness of the software. Once the flash system is set up and running at your shop, the only thing you need to do when you receive an order is to choose the proper cables/harness for the application, hook up the ECM to the off-board programmer and power up the flash system. At this point, once the flash software boots up on the PC, you would be prompted with a series of questions including vehicle year, make and model, as well as the vehicle’s full 17-digit VIN number. Due to the nature of the OE flash calibration software, you are only capable of choosing the latest and most updated version of the calibration software. This helps keep things simple and ensures that only the most recent updates get installed in the ECM. Once you click the “program” button, the PC takes over and performs both the programming and the verification check. The entire process averages approximately 10 to 15 minutes from the time that you get the ECM into your hands to the time you finish.

Inevitably, the progress and application of new technologies in the automobile forces us to do business in different ways and provide new services to our customers. Although implementing new procedures and services can be a painful experience at times, it is the only way to ensure our long-term survival in the automotive aftermarket business. Flash programming is here to stay, and with the software content of new vehicles accounting for approximately 20% of the vehicle’s purchase price, you can bet on the fact that the money to be made on flashing will only grow as the years go by.

GM FLASH APPLICATION CHART

Model Year 1993

 

VEHICLE MAKE

VEHICLE MODEL

ENGINE SIZE

ENGINE VIN (8th digit)

BUICK

Century

2.2

4

 

Regal

2.2

4

 

  

3.1

M

 

  

3.1

T

CHEVROLET

Beretta

2.2

4

 

Camaro

3.4

S

 

Cavalier

2.2

4

 

Corsica

2.2

4

 

Lumina

2.2

4

 

  

3.1

M

 

  

3.1

T

 

S/T Pick-up Truck

4.3

Z

GMC

S/T Pick-up Truck

4.3

Z

OLDSMOBILE

Cutlass Ciera

2.2

4

 

Cutlass Supreme

2.2

4

 

              

3.1

M

 

              

3.1

T

PONTIAC

Firebird

3.4

S

 

Grand Prix

2.2

4

 

            

3.1

M

 

            

3.1

T

 

GM FLASH APPLICATION CHART

Model Year 1994

 

VEHICLE MAKE

VEHICLE MODEL

ENGINE SIZE

ENGINE VIN (8th digit)

BUICK

Century

2.2

4

 

Regal

2.2

4

 

  

3.1

M

 

  

3.1

T

 

Roadmaster

4.3

W

 

  

5.7

P

CADILLAC

DeVille / Fleetwood

5.7

P

CHEVROLET

Beretta

2.2

4

 

Camaro

3.4

S

 

Cavalier

2.2

4

 

Corsica

2.2

4

 

Lumina

2.2

4

 

  

3.1

M

 

  

3.1

T

 

S/T Pick-up Truck

4.3

Z

GMC

S/T Pick-up Truck

4.3

Z

OLDSMOBILE

Cutlass Ciera

2.2

4

 

Cutlass Supreme

2.2

4

 

              

3.1

M

 

              

3.1

T

PONTIAC

Firebird

3.4

S

 

Grand Prix

2.2

4

 

            

3.1

M

 

            

3.1

T

 

More Articles in Underhood Service

article image
Jeep: Tapping Sound After Engine Warm Up
Some customers may ­experience a tapping sound from the engine compartment after ­engine warm up. Th...
 More»
Ford Focus: Engine Vibration at Idle
Some Ford Focus vehicles may exhibit an excessive engine vibration when idle. The vibration is most ...
 More»
 
© Copyright 2014 Babcox Media, Inc. All Rights Reserved
3550 Embassy Parkway, Akron, OH 44333
330-670-1234
(FAX) 330-670-0874