Power & ground
| Pin | Function | Signal Type | Voltage / Notes | |-----|-----------------------------|----------------|-----------------------| | B1 | 5V Sensor Reference | Output | +5V ±0.1V | | B2 | Manifold Absolute Pressure (MAP) | Analog Input | 0.5V (idle) – 4.5V (WOT) | | B3 | Throttle Position Sensor (TPS) | Analog Input | 0.5V (closed) – 4.5V (WOT) | | B4 | Intake Air Temp (IAT) | Analog Input | 0°C = 3.07V, 80°C = 0.28V | | B5 | Engine Coolant Temp (ECT) | Analog Input | 20°C = 2.5V, 90°C = 0.5V | | B6 | Camshaft Position (CMP) | Digital Input | Hall sensor: 0-5V square wave | | B7 | Crankshaft Position (CKP) | Digital Input | Variable reluctance or Hall | | B8 | Oxygen Sensor 1 (Lambda) | Analog Input | 0.1V (lean) – 0.9V (rich) | | B9 | Oxygen Sensor 2 (post-cat) | Analog Input | 0.1V – 0.9V | | B10 | Vehicle Speed Sensor (VSS) | Digital Input | 0-12V square wave | | B11 | Brake Switch | Digital Input | 0V (off) / 12V (brake pressed) | | B12 | Clutch Switch | Digital Input | 12V (disengaged) | | B13 | A/C Request | Digital Input | 12V when AC on | | B14 | Power Steering Pressure Switch | Digital Input | 12V under load | | B15 | Sensor Ground Return | Ground | 0V | | B16 | 5V Reference (secondary) | Output | +5V for external sensors | | B17-B32 | Manufacturer specific / unused | - | Check factory diagram |
While pin configurations vary slightly between vehicle manufacturers (e.g., a VW ME7.5 vs. a BMW ME7.2), the Bosch M7 ecosystem shares a standardized core wiring logic. The most critical pins for testing and diagnostics fall into four main categories. 1. Power Supply and Ground
Search for "Bosch M7 [your ECU number] pinout" or visit forums like PeugeotForums, RenaultForums.co.uk, or NicoClub (Nissan). Bosch M7 Ecu Pinout
Located typically at Pin 58 . Used for high-speed inter-module network communication.
Operates the fuel pump relay, ignition coils, fuel injectors, and idle speed actuators (stepper motors). General Pinout Overview (M7.9.7 Example)
Example A — 4-cylinder sequential injection (conceptual) Power & ground | Pin | Function |
The first thing that strikes you about the M7 pinout is its hybrid nature. Unlike its predecessor, the M1.5.5, which was purely about fuel and spark, the M7 pinout reveals a new master.
Before the ECU can communicate, it requires clean, stable power.
Pins 117 and 118 drive the electric motor inside the throttle body. Used for high-speed inter-module network communication
The ECU uses a connector (usually 3 rows of 27 pins). Rows (viewed from wiring harness side, latch at top):
| Test | Procedure | |------|------------| | | Key ON: A27=12V, A26=12V. Ground A3/A4 <0.2V to battery negative. | | Main relay test | With key ON, B27 should be 0V (relay energized). | | Crank no-start | Check A12/A13 (RPM sensor): should show 200-500mV AC while cranking. | | Lost communication | Measure resistance between B25 & B26: should be 60Ω (with other CAN nodes) or 120Ω (ECU alone). | | K-Line activity | Connect oscilloscope to B18 – should toggle 0-12V during diagnostic request. |
If in doubt, download the factory wiring diagram for your specific car. The principles in this guide will get you 90% of the way, but the last 10% requires model-year accuracy.