Bosch Me20 Pinout Verified Jun 2026
| Pin | Signal | Verified Function | Notes | | :--- | :--- | :--- | :--- | | | | | | | 3 | Ground | ECU Main Ground (Sensor) | Must be clean. Do not share with injectors. | | 8 | Ground | Power Ground (Injectors/Coils) | Heavy gauge wire. | | 37 | B+ | Permanent 12V (Memory) | Fused at 5A. | | 54 | B+ | Main Relay 12V (Power) | Switched via Motronic relay (Pin 56). | | SENSORS | | | | | 4 | TPS | Throttle Position Signal (0-5V) | Verified linear sweep. | | 21 | MAP | Manifold Absolute Pressure | 1-4.5V linear. | | 22 | IAT | Intake Air Temp (NTC) | ~2.5k Ohms @ 20°C. | | 40 | CLT | Coolant Temp (NTC) | Same curve as IAT. | | 52 | CKP | Crank Speed Sensor (Shielded) | VR sensor. Polarity matters! | | 43 | CMP | Cam Sensor | Hall effect (0-5V square wave). | | 50 | KS | Knock Sensor 1 | AC voltage. Shield to Pin 49. | | ACTUATORS | | | | | 7 | Injector 1 & 4 | Ground side switching | Saturated drivers (No ballast). | | 9 | Injector 2 & 5 | Ground side switching | | | 11 | Injector 3 & 6 | Ground side switching | | | 13 | Fuel Pump Relay | Ground trigger | Activates prime for 2 seconds. | | 23 | Ignition Output 1 | Coils 1 & 6 (Wasted spark) | Confirmed logic level (5V). | | 24 | Ignition Output 2 | Coils 2 & 5 | | | 25 | Ignition Output 3 | Coils 3 & 4 | | | 56 | Main Relay Control | Ground trigger | Switches Pin 54 power. |
| Pin | Function | Verified Status | |------|------------------------------|------------------| | B1 | Injector cylinder 1 | ✅ Verified | | B2 | Injector cylinder 2 | ✅ Verified | | B3 | Injector cylinder 3 | ✅ Verified | | B4 | Injector cylinder 4 | ✅ Verified | | B9 | Ignition coil output 1+4 | ✅ Verified | | B10 | Ignition coil output 2+3 | ✅ Verified | bosch me20 pinout verified
This is written for a technical audience (tuners, mechanics, DIY ECU swappers). It assumes the user has verified the data and wants to share it to build credibility. | Pin | Signal | Verified Function |
| Pin Number | Signal Name | Description | | --- | --- | --- | | 15 | TPS | Throttle position sensor | | 16 | MAP | Manifold absolute pressure sensor | | 17 | ECT | Engine coolant temperature sensor | | 18 | IAT | Intake air temperature sensor | | 19 | O2 | Oxygen sensor (lambda) | | | 37 | B+ | Permanent 12V (Memory) | Fused at 5A
| Pin | Signal Name | Verified Function | Behavior | | :--- | :--- | :--- | :--- | | | Injector Cyl 1 | Ground switched by ECU | 12V feed from main relay | | 3 | Injector Cyl 2 | Ground switched | 12V feed | | 4 | Injector Cyl 3 | Ground switched | 12V feed | | 5 | Injector Cyl 4 | Ground switched | 12V feed | | 8 | Ignition Coil 1 (A) | IGBT trigger | 0.5 – 3.5V dwell | | 9 | Ignition Coil 2 (B) | IGBT trigger | 0.5 – 3.5V dwell | | 10 | Ignition Coil 3 (C) | IGBT trigger (4-cyl wasted spark) | As above | | 11 | Ignition Coil 4 (D) | IGBT trigger | As above | | 16 | Idle Air Control (IAC) | Stepper motor coil 1A | 12V pulsed | | 17 | IAC Coil 1B | Stepper motor | 12V pulsed | | 18 | IAC Coil 2A | Stepper motor | 12V pulsed | | 19 | IAC Coil 2B | Stepper motor | 12V pulsed | | 24 | Main Relay Control | ECU grounds to power relay | 0V (relay ON) | | 25 | MIL (Check Engine) | Lamp ground control | 0V when active | | 30 | EVAP Purge Solenoid | PWM ground control | 12V feed present |
Pin 4 is generally used for the ignition switched signal.