The original ECU (computer), typically called a DME (Digital Motor Electronics) or Motronic, was an amazing advancement for the era. By utilizing computer control of the engine, consumers saw an increase in HP & TQ, an increase in fuel economy, a reduction in emissions, and a more behaved car with better power delivery and robustness to weather changes.
The original ECU/DME has been proven to be very capable, though circuit design tools, manufacturing processes, and component quality was very limited. As a point of reference, the DME (version ML3.1) was first released in the 1984 Porsche 911 - this was the same year that the Apple IIc was released!
Even with the inherent limitations of the time, the original ECU/DME has performed admirably. However, after nearly 30 years of operating in extreme temperatures, humidity, and vibration, the original units are dying. There are quite a few common issues, such as cracked solder joints, failing ignition and injection drivers, burnt and lifted electrical traces, water damage, etc.
Unlike nearly any other part of the car, options to repair/replace the original ECU/DME was limited to: finding a "hopefully" good working used one, send your original unit to a rebuilder, or attempt to find a 30 year old new old stock (NOS) unit.
Those were the only options - until now:
Seeing that the factory original ECU/DME units are dying, myself and another Computer Engineer and 944/951 enthusiast, Joe Baumbach of Focus 9 Technology, collaborated in an endeavor to build a new ECU. After a significant effort, a labor of love, and rigorous testing, both bench and in-car testing, Rogue Tuning is extremely excited to release our new ECU!
While there have been aftermarket ECUs for some time, they are a type of "universal ECU" which requires an entirely new wiring harness to be made and installed, often many new sensors are required - including costly crank angle setups, complete engine tuning to be done, and cannot run any chip/software designed for the original ECU/DME.
In contrast, the Rogue Tuning ECU is designed to be 100% backwards compatible with the factory ECU/DME! This ECU will plug right into the factory wiring harness, and accepts the standard E/EPROM chip that is in your current ECU/DME. Though the ECU is pictured with a Rogue Tuning, Inc. E/EPROM chip, we did not remove any compatibility with the original factory ECU/DME. Any chip that will run in the stock ECU/DME will also work 100% as intended in the new Rogue Tuning ECU!
The Rogue Tuning ECU is not a simple 're-draw' of the factory original. Our computer was designed and built from the ground-up, starting with a blank-slate. There are a myriad of advancements over the factory ECU/DME which have been implemented, all while keeping a laser-focus on compatibility.
To help illustrate some of the differences between the Rogue Tuning ECU and the factory original unit, let us take a look at the factory ECU/DME:
What should be immediately obvious is that the factory ECU/DME actually consists of two circuit boards connected by a ribbon cable, which are then folded-up in order to fit in the factory enclosure. At the time of design, through-hole technology was utilized. Because through-hole components are typically fairly large, the original ECU/DME required a lot circuit board surface-area, necessitating the dual-board design.
Let us take a closer look at the original factory ECU/DME hardware:
As you can see, each component takes-up a significant amount of room on the circuit board. Some of the components are even "doubled-up" using fly-over resistors. This was done because of the lack of room for these large components (look at the bottom left of the board for an example).
By contrast, take a look at the Rogue Tuning ECU:
The Rogue Tuning ECU primarily uses surface-mount technology, which has a significantly smaller footprint compared to the through-hole parts. With the much smaller components, we are able to fit everything onto one circuit board. Besides allowing for higher component-density, surface-mount has many benefits, such-as better mechanical integrity in a shaking/vibrating application, and lower electromagnetic noise emissions.
The Rogue Tuning ECU incorporates many advantages over the factory original unit by using modern design techniques and materials. For example, we incorporate a ground-plane, which reduces electrical noise and interference resulting in improved accuracy of sensor readings. The antiquated linear voltage regular was replaced by a high performance switching power supply (SMPS) for improved stability and reduced heat. The PCB is manufactured from modern FR4 material coated with an LPI mask, making it highly resistant to heat, water, vibration, and trace/pad de-lamination. Additionally, fully metalized vias allow solder to bond through-hole parts on the top, bottom, and through the circuit board. In-contrast, the factory ECU/DME only has a single solder pad connection on the bottom of the circuit board, which is susceptible to cracking with heat, vibration, and time.
Those with keen eyes will notice that there are some through-hole components on the new ECU. A few through-hole components are necessary to either maintain compatibility or meet performance standards when surface-mount equivalents are not available or possible. For example, to keep compatibility with the factory E/EPROM chip, a through-hole socket is required so the factory style chips can plug-in. In other cases, heat sinks are necessary that would not be compatible with surface-mount equivalents. That said, there is a huge difference in the through-hole manufacturing between the original ECU/DME, and the new Rogue Tuning ECU. The factory unit is only solder bonded on the bottom side of the board, vs the Rogue Tuning ECU which is bonded on the bottom, top, and center.
Here is a diagram to better illustrate the differences:
If we take another look at the new Rogue Tuning ECU from a different angle:
At the bottom of the picture, there are two large components. This is the ignition driver. The Rogue Tuning ECU uses modern IGBT transistors. These transistors have been developed specifically for switching high-power inductive loads - exactly what is required for an automotive ignition coil. (Click here for more information on the 944/951 ignition system) The ignition system on the Rogue Tuning ECU has been designed and tested for heavy-duty operation, and maximum ignition coil charge. The main drivers are also thermally connected to the DME enclosure, producing excellent heat dissipation. Furthermore, the ignition system is now protected with a fuse (a self-resetting fuse is optional), providing an added layer of protection to the ECU which the factory unit does not have.
Take note of the switches on the circuit board. These allow the Rogue Tuning ECU to be used in either a 924S/944NA (8-valve), or a 944 Turbo (951)! The switch near the ignition drivers determines which mode the ECU is in, 944 or 951. Further, a 951 owner can use this switch to bypass the KLR, in order to assist in finding a possible KLR fault! (it is not recommend to operate a 951 with the KLR bypassed for anything other than testing)
What about the other three switches? For those running Rogue Tuning software, these switches configure the operation of the rear-port.
Here it is from another angle, with and without the plug attached:
This plug allows a clean and easy way of connecting a MAP sensor, and/or Wide-Band O2 sensor to the DME - without cutting the factory wiring harness!
There is one more switch one the DME:
In the lower right-hand corner, there is a switch which allows the DME to utilize either a 24pin or 28pin E/EPROM chip. No modifications to the DME are necessary, only a simple flip of a switch.
Wonder what the silver cylinder in center-left of the previous picture is?
How about another look:
That cylinder is the new attachment hardware for the ECU enclosure! The original factory ECU/DME retains the enclosure by bending 10 metal tabs over to hold the enclosure cover to the base. After opening the factory ECU/DME few times, these metal tabs are fatigued and commonly break off. I have had many factory ECU/DMEs come through here with all of the tabs broken off, and duct-tape holding the enclosure together! By using a simple single-point retention, access to the DME for changes is vastly easier and will not wear-out, unlike the factory unit.
The Rogue Tuning ECU does not simply replace a few electrical components; we replace 98.5% of every electrical component! That said, in order to make the ECU, we do require three components from a factory original ECU/DME: The main system connector, the fuel quality switch, and one IC chip. As long as these three components are good, your core can be damaged or not working. We require the ML3.1 unit as a core. We cannot use the early (bolted-together enclosure) ML1.x ECU/DME as the core.
Our ECU comes with a Limited Lifetime Warranty, opening the lid/cover does not void the Warranty (unlike many rebuilt units), is extremely robust, plug-n-play compatible with all of your current equipment, and has 2014 design & manufacturing technology. We love our cars, and want to keep them on the road for as long as possible - our ECU is a huge asset to do just that.
The Rogue Tuning ECU is a direct replacement for these vehicles:
*** The early model 944 utilizes a non-compatible air flow meter (AFM). To use the new Rogue Tuning ECU, the car must be updated to the 1985.5+ AFM, or use the NA-Tune MAF kit we offer. The ECU will plug directly into the early 944 harness without issue.