Most calibrators work with maps. But if you want to understand why a map does what it does, you need to understand the signal path.
Step 1: Sensor input — Raw electrical signal enters the ECU. The ADC converts it to a digital value.
Step 2: Signal conditioning — The raw digital value is converted using a characteristic curve. For a MAP sensor, ADC count becomes kPa.
Step 3: Control algorithm — The conditioned signal becomes an input to boost targets, rail pressure maps, SOI tables.
Step 4: Output calculation — The algorithm produces a demand signal — how much fuel, what timing, what rail pressure.
Step 5: Actuator output — The output driver converts the demand into a physical signal.
Why this matters for calibration
When a map “doesn’t seem to do anything,” it’s usually because the signal isn’t reaching that map, or the output is being overridden downstream. Understanding the data flow tells you where to look.
When you work in Ghidra, you can trace this entire chain in the firmware. In Ghidra Fundamental, we start with firmware structure and build this understanding from the ground up.