Me7.4.5 — Pinout

On most VAG cars, the ECU lives under the plastic rain tray panel at the base of the windshield (driver’s side for LHD, passenger side for RHD). To access the connector:

The ME7.4.5 pinout is the backbone of any successful 1.8T tuning or diagnostic project. While the ECU is largely reliable, wiring mistakes are the #1 cause of “phantom” performance issues. Keep this guide bookmarked, always use a multimeter to confirm continuity, and never assume a pin is unused without consulting a factory wiring diagram (which can vary slightly for automatic transmission or quattro systems).

With this detailed pin reference in hand, you are ready to tackle any wiring challenge the ME7.4.5 throws your way—whether you’re chasing a misfire, installing a standalone ECU, or swapping this legendary engine into a project car.

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For vehicle-specific pin variations (e.g., Audi TT Quattro vs. FWD Golf), leave a comment with your engine code (AUM, BAM, APX, AUG) and model year.

The Bosch ME7.4.5 is a common Engine Control Unit (ECU) found in PSA Group vehicles (Citroën and Peugeot), specifically managing 1.6L 16V engines like the TU5JP4. 🛠️ Key Connection Feature: Boot Mode me7.4.5 pinout

A primary "feature" often sought for the ME7.4.5 pinout is the ability to put the unit into Boot Mode for reading/writing flash memory.

Pinout Requirements: Standard bench connections typically involve powering pins POL4 and POL5 (+12V) and establishing a K-Line or CAN communication path.

Hardware Modification: To enable Boot Mode, you must internally modify the board by adding two 6k8 ohm resistors and removing one existing resistor. MCU: This ECU typically uses the ST10F275 microprocessor. 📋 General Pinout Overview

While specific pin assignments can vary slightly by vehicle model (e.g., Citroën C4 vs. Peugeot 207), a general bench-testing pinout often includes: Common Pin(s) +12V (Main Power) POL4, POL5 Ground ECU Case or specific Ground pins Ignition (+15) Specific to vehicle harness K-Line (Diagnostics) Used for OBD/Bench communication ✨ Advanced System Features On most VAG cars, the ECU lives under

The ME7.4.5 is more than just a controller; it manages complex engine strategies:

Motorised Throttle Management: Eliminates the physical accelerator cable, using a "driver's wish" voltage from the pedal sensor to adjust engine torque.

Power Latch Function: Keeps the ECU powered for at least 15 seconds after the ignition is turned off to save fault memories and adaptive parameters.

Torque Compensation: Automatically adjusts idle speed when it detects high-pressure loads from the power steering pump during full-lock turns. I can help more effectively if you tell me: Are you trying to do an IMMO OFF (immobiliser bypass)? Are you performing a bench flash or a remap? Need More Help

| Function | Pin (T121) | Notes | |----------|------------|-------| | K-line (diagnostics) | 26 | ISO 9141-2 | | CAN low | 24 | Usually for ABS/TCU | | CAN high | 25 | | | Ignition switch +12V | 1 (via main relay) | Terminal 15 | | Permanent +12V | Also on separate high-current pin | Terminal 30 | | Ground | 2, 32, others | |

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).

| Pin Number | Pin Name | Description | | --- | --- | --- | | 1 | VBATT | Battery voltage supply | | 2 | GND | Ground | | 3 | VREF | Voltage reference |

If you want, I can:

If using the ME7.4.5 in a standalone configuration: