When it comes to module reprogramming, there is so much information out there for busy shops and technicians to keep up with. Even if you confine your focus to just the power requirements related to module reprogramming, it can still be overwhelming. Different OEs call for different power needs, in terms of both system voltage and available current, to keep up with expected demand. Even within a single make, the power requirements can shift drastically from model to model and among different model years. So, this month, we thought we would address a few of these issues and bring in a few outside resources to (hopefully) help shed some light on this topic.
The Key is to Give the System What it Wants and Needs
Since introducing our flashing power supply Models PL6100 and PL6800, one of the key things we have tried to impress upon service operations is the need to calibrate the output of the power supply to specifically meet the OE-recommended power parameters for the vehicle under service. When it comes to meeting the recommended power parameters, it starts with the OE-recommended voltage environment in which the reflash will take place. The various manufacturers recommend very different voltage targets, which can include: >12V, 13.4V, 13.7V, 14.2V, etc. It is critical that a service operation utilize a power supply that can dial in the specific recommended voltage target to 0.1V. PRO-LOGIX flashing power supplies can support system voltages from 13.1-14.9V, adjustable in 0.1V increments. This allows an operator to exactly match the OE-recommended system voltage. The second key component of the recommended power parameters is the current (amperage) available to support the system by offsetting the loads that occur during the reflash event. Each OE has a recommended minimum current required to successfully support their reflash routines. These minimum current requirements vary from 55A to 100A, as well as just about everything in between. The beauty of power supply operation is that you don’t need different models to support different current requirements. You just need to meet or exceed the highest current requirement among the makes you service. This is because a flashing power supply doesn’t work like a battery charger, where you set the output to 20A and it delivers a 20A charging routine. Instead, the flashing power supply is voltage-driven, such that you set the desired voltage level, say at 13.7V, and the power supply will provide the current necessary (up to its max output) to maintain that level, raising and lowering its current output based on system demand. With 100A max output with no limitation on the length at which they can operate at 100A, our PL6100 and PL6800 models can support the flash reprogramming power needs of virtually any make or model on the road today. Realistically, the output should really be called 0-100A on demand, as they will manage the output such that exactly the amount of power needed to maintain the desired voltage is provided. So, if the demand required to maintain 13.7V is 8A, the power supply will output 8A. If load demand increases and 62A is needed to maintain 13.7V, then the PL6100/PL6800 increases its output to 62A. And, the PL6100 and PL6800 react quickly and precisely to changes in load demand, which is critical, as seen in the below referenced article. If the recommended voltage level is not maintained, the reflash event can get derailed, resulting in the need to start all over again (best case) or a bricked module (worst case), as seen in the below TSB article related to reprogramming the Porsche Cayenne, “If a low voltage condition occurs while being programmed, …the module may be rendered permanently inoperable.” Also noted in the TSB are the specific power parameters required for a successful reflash event:
“The electrical system of a well-equipped vehicle can draw more than 40 AMPs of current with the ignition switched on. It is important that a clean microprocessor-controlled power supply be connected to a vehicle whenever the ignition is switched on and the vehicle’s engine is not running. Never use an unregulated, high output battery charger on these vehicles. The power supply must have a minimum continuous output capability of 40 Amps at 13.8 VDC under load. With the ignition switched on, the output of most power supplies will be 14.2 to 14.5 VDC. A vehicle voltage below 13.8 VDC under load may indicate that the capacity of the power supply has been exceeded. The voltage supplied to the vehicle must never exceed 14.5 VDC for more than a few moments. A sustained voltage above 14.5 VDC will dry out and permanently damage the glass mat in the cells of the AGM battery.”
It is critical that, when performing these advanced vehicle programming applications, you are able to exactly meet the required power parameters for the vehicle being serviced. A precise, microprocessor-controlled power supply, such as our PL6100 or PL6800, is essential equipment for this task.
Power Requirements Vary By Make (and Model)
It is really important to understand that providing power for optimal reprogramming support is not a one size fits all proposition. As noted previously, the OE-recommended power parameter can be very different from one make to another and can even vary significantly from model to model with a given brand. It is important to ensure that you know what the power need is for the vehicle you plan to reflash, whether you get that from your service information provider or directly from the OE. Our next resource provides a rundown of the power requirements for several makes and models. While it is not an exhaustive listing by any means, it is filled with useful information and also illustrates just how much the power demand can vary. For instance, Honda specifies the connection of a jump starter to augment the battery and keep it from dropping below the required voltage threshold (vs. the use of a stable power supply). They are the only North American vehicle brand we know of that specs this routine. In another example, Subaru mandates that the diagnostic tool not be connected to the vehicle until the system has stabilized at 13.5V. This is a good article to bookmark and have handy as a reference.
Tips and Tricks for BMW Reprogramming Similar to Honda, it has always felt like BMW has been on an island when it comes to reprogramming/reflashing. They pioneered the process of reflashing multiple modules at the same time. They also have always led the way when it comes to power demand, often specifying required available current 50-70% higher than other OEs. These two factors are likely related, of course. The uniqueness and complexity of BMW reflashes have earned those vehicles a reputation for problematic programming and negative outcomes. Andrew Markel addressed these issues in a recent article on import-car.com, offering several things to remember when programming BMW modules. He distinguishes between an encoding event and a reprogramming/reflashing event. He addresses key service tips, such as rolling the latches on the doors and trunk to prevent an inadvertent power draw, the need for the driver’s seat belt to be latched and a tip to put the wipers in the up position. Who would have guessed? We would say that the best thing about this article is that it illustrates all the aspects of a reprogramming event that need to be taken into account before the actual software updates are performed. It is a great article and we highly recommend it.
PRO-LOGIX models PL6100 and PL6800 provide stable power, on-demand up to 100 amps, to a vehicle electrical system for optimal module reprogramming support. They maintain the vehicle electrical system voltage at a preset level, increasing output in response to system load increases. Each model features a voltage output range of 13.1-14.9V, adjustable in 0.1V increments, allowing the operator to dial the output in exactly as specified by the supplier of the vehicle under service. They feature fast load responsiveness for ultra-quick recovery from system demand increases with minimal voltage ripple, providing a clean flow of power to the vehicle without risk of programming interference. The only difference between the two models is that the maximum charging rate on the PL6800 is 100A, perfect for heavy-duty battery packs, versus 60A for the PL6100, which is designed for use in light and medium duty vehicle application. Their power supply modes are identical. As all of the above references illustrate, vehicle reprogramming can be painstaking and difficult. One great way to reduce the complexity out of this application is by choosing a power supply that puts you in control and gives the vehicle’s system exactly what it needs. That’s PRO-LOGIX.
Have you run into power issues while reprogramming? Do you have any tips and tricks that other shops or technicians would benefit from that you’d like to share? If so, we’d love to hear about it in the comments below.