The Bosch ME7.4.5 is a common Engine Control Unit (ECU) used in Peugeot and Citroën vehicles, particularly for the 1.6 16v engine. It belongs to a generation of digital ECUs that manage engine torque, sequential multipoint injection, and static ignition while communicating via the CAN network with other vehicle systems like the BSI and ABS. Critical Bench Pinout Connections
For bench work—such as reading, writing, or diagnostics—you typically connect to Plug C (the 32-pin connector). +12V Power Supply: Pin H2 Ignition (+12V): Pin F4 Ground: Pin H4 K-Line (Data): Pin B4 CAN-Bus: CAN High: Pin A3 CAN Low: Pin A4 Programming & Boot Mode
To perform advanced tasks like IMMO OFF or full cloning, the ECU often needs to be put into Bootstrap Mode. This requires internal modifications to the circuit board:
Opening the ECU: The cover must be carefully pried open to access the internal memory and microprocessor.
Internal Modifications: Some guides, such as those from Piasini Engineering, specify adding two 6k8 ohm resistors and removing one existing resistor to enable boot mode. me7.4.5 pinout
Full System Reading: Tools like DFB Technology allow for a full read and write of the Micro and EEPROM (typically a 95320 eeprom) via these pinout connections. Essential Precautions
Accuracy: Always verify pin locations from a front-facing perspective of the connector plug to avoid damaging sensors or the internal traces of the ECU.
Power Sources: When using specialized tuning cables (like those for Trasdata), ensure the power LED is active. If using a metal positioning frame, the ECU might be powered through the frame rather than the main connector pins.
Immobilizer Bypass: Many users seek the pinout for "Immo Off" solutions, which often involve using an emulator (like the Julie emulator) to bypass transponder signal issues. The Bosch ME7
Are you planning to perform a full clone or just simple diagnostic reading on this ECU?
This is the most common failure point. If the ground points on the engine block or chassis are corroded, the high current seeks alternative paths.
Below is a detailed reference for the most critical pins found in the standard ME7.4.5 wiring loom. Please note that wire colors may vary depending on the vehicle manufacturer (Peugeot vs. Fiat).
Use pin 55 (N75 boost control) as a trigger for a relay, but only if you re-tune to avoid boost oscillation. pins are numbered left-to-right
The ME7.4.5 utilizes a single multi-pin connector housing (often gray or black depending on the specific supplier variant, though typically Gray for Bosch ME7.x).
Below is the definitive pinout for the ME7.4.5. Pins are numbered 1 through 121. Pins marked “---” are unused in most manual-transmission 1.8T applications.
| Pin | Connector | Signal Name | Description | Typical Function | |------|-----------|----------------|--------------------------------|--------------------------| | 1 | A | Ground | Sensor ground | - | | 2 | A | EVAP Canister Purge Valve (N80) | Duty cycle control | Emissions | | 3 | A | Ground | Power ground for injectors/coils | - | | 4 | A | +12V Battery | Permanent power (Terminal 30) | ECU memory | | 5 | A | +12V Switched (Terminal 15) | Switched via ignition | Wake-up signal | | 6 | A | CAN-High | Drivetrain CAN bus | ABS, Instrument cluster | | 7 | A | CAN-Low | Drivetrain CAN bus | ABS, Instrument cluster | | 8 | A | Brake light switch signal | Input | Brake pedal | | 9 | A | Clutch pedal switch | Input | Cruise control / starting | | 10 | A | A/C compressor request | Input | Climate control | | 11 | A | Radiator fan activation (low speed) | Output | Cooling | | 12 | A | Radiator fan activation (high speed) | Output | Cooling | | 13 | A | --- | Not used | - | | 14 | A | Alternator excitation signal | Output | Charge warning | | 15 | A | Diagnostic K-Line (ISO 9141) | Bi-directional | OBD2 communication | | 16 | A | --- | Not used | - | | 17 | A | --- | Not used | - | | 18 | A | --- | Not used | - | | 19 | A | Fuel pump relay control | Output | Activates FP relay | | 20 | A | Engine speed output (RPM signal) | Output | Tachometer cluster | | 21 | A | MIL (Check engine light) | Output | Warning lamp | | 22 | A | EPC light | Output | Electronic Power Control | | 23 | A | +5V Sensor supply | Reference voltage | For MAP, TPS, etc. | | 24 | A | --- | Not used | - | | 25 | A | --- | Not used | - | | 26 | A | --- | Not used | - | | 27 | A | --- | Not used | - | | 28 | B | Knock sensor 1 (cyl 1 & 2) | Signal input | Ignition timing control | | 29 | B | Knock sensor 2 (cyl 3 & 4) | Signal input | Ignition timing control | | 30 | B | Sensor ground (shield) | For knock sensors | - | | 31 | B | Intake Air Temp (IAT) | Signal input | Inside MAF or TMAP | | 32 | B | Engine Coolant Temp (ECT) | Signal input | Temperature compensation | | 33 | B | Shield ground | For crank/cam sensors | - | | 34 | B | MAF signal | Frequency/duty cycle | Airflow metering | | 35 | B | MAF ground | Sensor return | - | | 36 | B | G28 Engine speed (crank sensor) | Differential signal (-) | RPM base timing | | 37 | B | G28 Engine speed (crank sensor) | Differential signal (+) | RPM base timing | | 38 | B | G40 Camshaft position sensor | Hall effect signal | Sequential injection | | 39 | B | Throttle position sensor (G187) | Signal 1 (closing) | ETC | | 40 | B | Throttle position sensor (G188) | Signal 2 (opening) | ETC redundancy | | 41 | B | Accelerator pedal position (G79) | Signal 1 | Driver demand | | 42 | B | Accelerator pedal position (G185) | Signal 2 | Redundant signal | | 43 | B | MAP sensor (Integrated) | Boost pressure signal | Inside ECU case | | 44 | B | MAP sensor ground | Internal ECU | - | | 45 | B | External MAP (for some models) | Boost input (rare) | - | | 46 | B | --- | Not used | - | | 47 | C | Injector cylinder 1 | Output (ground switch) | Fuel delivery | | 48 | C | Injector cylinder 2 | Output (ground switch) | Fuel delivery | | 49 | C | Injector cylinder 3 | Output (ground switch) | Fuel delivery | | 50 | C | Injector cylinder 4 | Output (ground switch) | Fuel delivery | | 51 | C | Ignition coil 1 (power stage) | Output | Spark | | 52 | C | Ignition coil 2 (power stage) | Output | Spark | | 53 | C | Ignition coil 3 (power stage) | Output | Spark | | 54 | C | Ignition coil 4 (power stage) | Output | Spark | | 55 | C | N75 Boost control valve | PWM output | Wastegate control | | 56 | C | Idle Air Control (N71) | PWM output (if not DBW) | Idle stabilization | | 57 | C | Secondary air injection pump relay | Output | Cold start emissions | | 58 | C | Secondary air injection valve (N112) | Output | Air diverter | | 59 | C | O2 sensor heater (Bank 1, Sensor 1) | Output | Lambda heating | | 60 | C | O2 sensor heater (Bank 1, Sensor 2) | Output (post-cat) | Heating | | 61 | C | O2 sensor (Sensor 1) signal | Input (0-1V or wideband) | AFR | | 62 | C | O2 sensor (Sensor 1) ground | Ground for lambda | - | | 63 | C | O2 sensor (Sensor 2) signal | Input | Post-cat monitoring | | 64 | C | O2 sensor (Sensor 2) ground | Ground | - | | 65 | C | Fuel tank pressure sensor | Input | Leak detection | | 66 | C | --- | Not used | - | | 67 | C | --- | Not used | - | | 68 | C | --- | Not used | - | | 69 | A | +12V Switched (Terminal 15) duplicate | Redundant | Safety | | 70 | A | Ground | Power ground | High current | | 71 | A | Ground | Power ground | High current | | 72 | A | +12V Battery duplicate | Redundant main power | - | | 73 | A | +12V Battery duplicate | Redundant main power | - | | 74-121 | --- | Various unused or vehicle-specific pins | (e.g., cruise control, A/C pressure) | Check wiring diagram |
Disclaimer: Pins beyond 74 are often empty on manual 1.8T ME7.4.5 ECUs. For A/T cars, pins 84-89 may carry TCU CAN data.
The ME7.4.5 utilizes two main connectors plugged into the side of the unit.
Note: Pin numbering follows standard Bosch conventions (looking at the ECU pins from the harness connector side, pins are numbered left-to-right, top-to-bottom).