The Injection Correction Maps are main part of fuel injection control strategy in modern gasoline engine management systems, especially in Bosch ME7, ME9, ME17, and MED17 ECUs. The main purpose of these maps is to ensure that the actual injected fuel mass (mg/stroke) matches the requested fuel mass calculated by the ECU torque and lambda model specially in close loop condition ,  notwithstanding fluctuation in operating conditions such as battery voltage, fuel pressure, injector dead time, intake air temperature, coolant temperature, and engine load.

In electronic fuel injection systems, the ECU does not directly inject fuel based on fuel mass; instead, it controls the injector opening time (Injection Pulse Width), usually measured in milliseconds (ms). The relationship between injected fuel mass and injector pulse width can be simplified as:

although , this relationship is not  linear in real world conditions because injector behavior depends on battery voltage, injector coil response time, fuel pressure differential, fuel temperature, and injector non linear flow characteristics. For this reason, ECUs use multiple Injection Correction Maps to compensate for these variations.

One of the most important corrections is Battery Voltage Correction (That we have map correction for it in Dump), because fuel injectors are electromagnetic solenoid valves, and their opening delay depends strongly on supply voltage. At low battery voltage (for example 11 to 12 V), the injector opening time increases due to slower solenoid activation, meaning the ECU must compensate by increasing injector pulse width.

This relationship is often represented in a map with axes such as:

• Battery Voltage (V)
• Injection Time or Correction Factor

Another important correction is Fuel Pressure Correction, because injector flow rate depends on the square root of pressure differential across the injector:

Where:

• ΔP\Delta PΔP = Fuel pressure difference between fuel rail and intake manifold (bar)

If fuel pressure increases, injector flow increases, and the ECU must reduce injection time to maintain the same fuel mass. Conversely, if fuel pressure drops, injection time must increase.

Additional correction maps may include:

• Intake Air Temperature Correction (°C)
• Coolant Temperature Correction (°C)
• Engine Load Correction
• Short Pulse Width Non-Linearity Correction
• Injector Dead Time Compensation

These correction maps are extremely important in closed-loop fuel control systems, where the ECU continuously adjusts fueling based on feedback from the oxygen sensor (Lambda sensor). The ECU calculates a theoretical fuel mass based on air mass and target lambda:

If injection corrections are not properly calibrated, the actual injected fuel will not match the requested fuel mass, leading to:

• Incorrect lambda control
• Fuel trims drifting (STFT / LTFT)
• Poor fuel economy
• Increased emissions
• Engine hesitation or unstable idle
• Incorrect torque calculation in torque-based ECUs

In Bosch ME torque-based ECUs, fuel injection is closely linked with the torque model, air mass calculation, lambda control, and ignition strategy, so incorrect injection correction calibration can affect not only fueling but also torque calculation and engine load modeling.

In this advanced WinOLS course, we teach you how to find Injection Correction Maps in WinOLS without using Damos/ A2L or MapPacks by analyzing binary patterns, data structures, and typical correction table rhythm. You will learn how to identify battery voltage correction maps, fuel pressure correction maps, and temperature correction tables, how to determine their axes, and how to calculate correct factor and offset to convert raw values into real number units such as milliseconds (ms), volts (V), bar, and correction factors.

Most importantly, we explain when these maps need to be modified during custom tuning, such as when:

• Larger fuel injectors are installed
• Fuel pressure regulator is modified
• Ethanol or different fuels are used
• High performance turbo setups require different injection scaling
• Injector dead time characteristics change

Understanding Injection Correction Maps is very important because accurate fuel injection control is the foundation of lambda control, torque calculation, combustion stability, and engine reliability. A professional ECU tuner must fully understand these correction strategies before performing advanced fuel, ignition, and boost tuning.