This technical guide breaks down the essential steps on how to write your own WinOLS mappack on EVC WinOLS, as discussed in our recent VTA Academy webinar. Whether you are working on a Bosch EDC17 C46 or a similar diesel ECU, understanding how to identify, label and convert raw data is the foundation of professional remapping.
Why the Mappack is Your Foundation
A Mappack is a structured collection of identified maps within an ECU’s hex data. Without it, you are tuning “blind.” While automated software can help, a professional tuner must know how to pick apart the ECU manually to locate specific tables for fuelling, boost, and torque.
Identifying Potential Maps
When you first import a project into WinOLS, the software performs a background search for “Potential Maps.” These are identified through:
- Bosch Recognition: Pattern matching based on known Bosch structures.
- Statistical Recognition: Logic based on data patterns that look like maps.
Pro Tip: Sort your potential maps by size. In ECU logic, the largest maps (e.g. 20×20) are typically the most important as they cover the broadest range of RPM and load points. Smaller maps are often used for specific corrections or “limp mode” strategies.
Key Maps Required for a Stage 1 Diesel Tune
To build a functional Stage 1 Mappack, you must identify and move the following maps from “Potential” to “My Maps”:
1. Driver’s Wish (Torque Request)
This map translates the driver’s throttle input into a torque request.
- Axes: Throttle Position (TPS %) vs Engine Speed (RPM).
- Logic: Higher values at lower RPMs that taper off as the engine reaches its limit.
2. Torque Limiter
The “gatekeeper” map. It defines the maximum torque the engine is allowed to produce to protect the drivetrain.
- Axes: Typically RPM vs Atmospheric Pressure.
- Visual: Looks like a classic torque curve, rising aggressively, peaking then trailing off.
3. Injection Duration (Pulse Width)
This map tells the injector how long to stay open. It is a calibration map that the ECU uses as a lookup table.
- Axes: Rail Pressure vs Fuel Quantity (IQ).
- Key Logic: As rail pressure increases, the duration (time) required to inject the same amount of fuel decreases.
4. Start of Injection (SOI)
Determines the crank angle at which fuel injection begins.
- The Sign Function: In WinOLS, SOI maps often require the Sign Function to be enabled to display negative values correctly (representing degrees before or after Top Dead Centre).
5. Boost Pressure and Limiters
Identifies the target turbo pressure and the ceiling limit to prevent overboost.
- Axes: RPM vs Fuel Quantity.
- Conversion: Bosch ECUs typically display raw millibar values (e.g. 2300 mbar = 1.3 bar of boost + 1 bar atmospheric).
Applying Conversions and Factors
Raw hex data is rarely “human-readable.” To make the data tuneable, you must apply conversion factors. Common Bosch factors include:
- Torque: 0.1 (e.g., a value of 3200 becomes 320 Nm).
- Fuel (IQ): 0.01 or 0.1 depending on the ECU generation.
- RPM: 0.5 (common for Bosch EDC17).
- TPS %: 81.92 (a calculation based on 8-bit/16-bit bitrates).
FAQ: Common WinOLS Questions
How do I know if fuel is measured in (mm3 (volume) or mg/str (mass)?
For a Stage 1 tune, the difference is marginal as the values are very similar. However, for Stage 3+ custom builds with larger injectors, you must refer to a Damos or A2L file for exact unit confirmation.
Can WinOLS find DTC (Diagnostic Trouble Code) tables automatically?
No. DTC removal is an advanced process involving individual bytes of data and relational “error class” data elsewhere in the ECU. It is not recommended for beginners to simply “zero out” codes without understanding the logic.
What is the fastest way to build Mappacks for similar ECUs?
Once you have defined a map, you can save the configuration. WinOLS allows you to “propagate” or transfer map properties to other similar files, significantly speeding up development for future vehicles.
What is WinOLS tuning software for ECU?
WinOLS is a professional-grade program specifically written to modify the memory contents of Engine Control Units (ECUs). Unlike “plug-and-play” tools, it allows tuners to pick apart the raw hexadecimal data of an ECU to find, name and edit specific maps for parameters like turbo pressure, fuel injection, and torque limits. It is widely considered the most advanced tuning editor available.
How to connect WinOLS to ECU?
WinOLS is an editing software, not a reading/writing tool. To connect to an ECU, you typically use a separate hardware interface (like Alientech KESS3) to “read” the file from the vehicle. You then import that file into WinOLS for editing and use the hardware again to “write” the modified file back to the ECU.
How much does WinOLS cost?
Pricing depends on the version and any additional modules or credits you require.
- WinOLS 5 Full Version: Typically costs around £765 to £1,000 for a single-user license.
- Annual WinOLS Subscription: Updates usually require an annual fee of approximately £75 / €75 per machine.
- Additional Credits: Checksum plugins or “Super Mappacks” can cost extra, ranging from small fees to several hundred pounds.
Is WinOLS legal to use?
Yes, WinOLS is legal proprietary software developed by EVC Electronic in Germany. However:
- Licensing: It must be legally purchased through authorised distributors. Using cracked versions or torrents is illegal and carries significant security risks.
- Usage: The legality of the tuning itself (the changes you make to a vehicle) depends on your local regional laws regarding emissions and road safety.
Can WinOLS damage my ECU?
The software itself does not damage ECUs; however, user error can.
- Incorrect Data: Writing wrong values (e.g. too much boost) can cause mechanical engine failure.
- Checksum Errors: If you modify a file and do not correct the “checksum” (a mathematical safety check), the car may not start, or the ECU could become “bricked” (unresponsive).
- Clone Tools: Using “fake” or clone hardware to write your WinOLS files back to the car is a major cause of ECU damage.
Can I reprogram my ECU myself?
Technically, yes, but it is a “sandbox” for professionals with a steep learning curve. As Simon mentioned in the webinar, jumping in without training is a “world of hurt” because of the mathematical logic and conversion factors required to make the raw data readable. Proper training (like the VTA Remap 101 Academy) is highly recommended before attempting to write your own files.
About the Author
Simon White is the Technical and Managing Director of VIEU with a dedication to research and development, he is regularly up-to-date with the latest tuning tools, software and techniques. Simon is an experienced tuner and has been recognised as an EVC Platinum Certified Trainer. He regularly delivering vehicle tuning training courses around the world for the VIEZU Technical Academy.
