To flash, or not to flash? That is the question
The Dangers of ECU re-mapping – Flash Tuning
by Andrew Bourne
Most of us who tow caravans or other loads with our 4WD’s are familiar with the need to improve the performance of our tow vehicle. The last 15 years has seen a major change in engine design and engine management systems, this is especially so for diesel engines. They have evolved from being naturally aspirated to multiple turbocharged and intercooled, from mechanical fuel injection systems to electronic control injection systems.
With this evolution two major developments have occurred – vastly improved engine performance for towing, and the ability to alter the engine’s performance by changing the management system’s parameters electronically.
What is a “Chip”
The term “chip” is used in a very general sense these days. It comes from the early practice of physically adding or changing a chip (microprocessor) to the printed circuit board of an engine’s management computer to enable changes to be made. This practice is not common these days but has been replaced by a variety of methods to squeeze more out of the engine, but the name “chip” has stuck and is used loosely to describe pretty much any means to change performance electronically.
Most “chips”, or more correctly called modules, are a box of electronics that is actually a computer in itself that is separate to the vehicle ECU and connected into the fuel injection system, turbo boost sensor, exhaust temperature sensors, etc by means of a harness and connector plugs. Different modules use different ways to connect and to alter things like fuel quantity but they are essentially “piggy-back” systems that can be removed pretty easily.
Generally speaking; piggy-back modules change the fuel mapping by either increasing the fuel pressure in the system, or by altering the duration of injection. Both methods increase combustion pressure within the cylinder to provide more downward force on the pistons, the result is more power and torque. A tow vehicle with more power and torque does the job better and often there’s a bonus positive result in fuel economy.
Defining the Problem
In recent years there has been a massive influx of ECU re-mapping emerge. This practice of downloading a different map into the vehicle’s Electronic Control Unit is often called “re-flashing”. The sheer volume of re-flashing companies that have popped up overnight could accurately be described as an epidemic. With so many companies out there it’s very difficult to know where to even start, never mind who you can trust with your $90,000 SUV to weave their particular mix of magic on!
Every city and many country towns in Australia & New Zealand have seen local mechanical businesses jump on board the re-flashing train. In many cases they have paid an overseas programmer for the licence to download a program into customer’s vehicles, and in reality have no idea of what has been changed. The companies they buy the licence from invariably have a slick website and all claim to be the best on the business…… Ho-hum
I must be fair here and point out that there are probably a few clever programmers who have not only successfully hacked the manufacturers ECU program, but have the necessary knowledge to do an excellent job of changing parameters to achieve a safe increase in engine performance. However….. the scary part is there are many, many more who are nothing more than digital cowboys who have the IT ability but not a lot of knowledge or experience with internal combustion engines. If your alarm bells aren’t ringing they should be.
So, what are the pro’s and con’s of re-mapping / re-flashing, and how does this compare to a module? As mentioned previously; Piggy-back modules change fuel mapping & in some cases turbo boost pressure. Most have no influence on injection timing, though this is possible. Re-mapping changes fuel mapping too, but also opens up the possibility to change many other parameters because the manufacturers own DNA can be “tweaked”.
This can be an advantage but also a disadvantage, depending on the skill and knowledge of the person pushing the buttons. Pushing the limits can be attractive short term but the flip side is compromised longevity. The worst example of this I’ve heard of is a re-mapper turning off DTC’s (Diagnostic Trouble Codes) to achieve maximum results without logging codes.
ECU re-flashing Pro’s
- The possibility to change many ECU parameters exists. (See also as a Con!)
ECU re-flashing Con’s
- Confusing variety of brands exist, some with a very short history and few runs on the board.
- Technical back-up can be scarce. Often the installer buys the file from overseas so gaining technical support from someone who knows something is difficult or even impossible.
- Footprint is left on ECU.
- Difficult to diagnose if an engine symptom is re-flash related or not. I.e. cannot simply be disconnected to revert to standard engine settings.
- It can be difficult to reverse the procedure. This depends on the re-flash.
- Re-flash can be lost if the ECU has an update performed by the manufacturer. Conversely; the re-flash can prevent a factory update to be performed at all. This depends on the re-flash.
- No manual adjustment by the vehicle owner is possible after the re-flash is performed.
- If the vehicle is sold the re-flash goes with it. I.e. you cannot remove the re-flash file and sell it to re-coupe some of its cost.
- The ability to change many ECU parameters can push limits to extremes when in bad hands.
Module Pro’s
- Known brands that have proven history are available.
- Technical support is available & local.
- No footprint on the ECU
- Vehicle diagnostic trouble codes left in place.
- Easily disconnected if required to revert back to standard.
- Can be adjusted manually
- Not affected by factory ECU updates.
- Can be sold to recoup some of its initial cost if the vehicle is sold.
- May be able to be reprogrammed for a different vehicle in some cases.
Module Con’s
- Some parameters not accessible downstream of the ECU
Conclusion:
If you want better performance from your vehicle you should ask yourself some questions relating to the pro’s & con’s above. Although the re-flashers claim they are the bee’s knees of performance, and that modules are old hat, there are some negatives that should be considered before diving in. Ultimately, ECU Flash Tuning can be a very dangerous and costly addition to your vehicle. If you’re wanting more power, the safe choice is a module, installed by a trusted diesel engineer.
See information on STEINBAUER POWER MODULES here
