Chapter 13 — 121-Pin Wiring Harness Cross-Reference & Platform Repinning Matrix#
| Part | IV · Signals, Telemetry & Getting Data In and Out |
| Source | DOC 35 § 13 |
| Contents | Critical Pinout Divergences Between Platforms and 1 more |
| Calibration symbols | DSLGRAD, DSLOFS, TABG_W, GANGI, G235, J104, J271, J285, J293, N112, N205, N249 … +15 more |
| ECUs covered | 06A906032LP |
| Size | 1 table · 1 code/diagram · ~1,260 words |
The 121-pin harness, platform divergences, and a full repin matrix.
To support the physical conversions detailed in Section 9 (adapting donor ECUs from Audi A4 B6 8E0, Audi TT 8N0, or Audi A6/Passat 4B0 to transverse Mk4 Golf/Jetta 06A specifications), this section provides the definitive pinout comparison across all 121 pins of the Bosch ME7.5 connector housing.
| Chamber A: 81-Pin Engine Harness (Pins 1–81) | Chamber B: 40-Pin Body Harness (Pins 82–121) |
|---|---|
| • Injectors, Ignition, Lambda LSU 4.2, Sensors | • Power, Ground, CAN Bus, K-Line, Pedal, Relays |
13.1. Critical Pinout Divergences Between Platforms#
Before installing a cross-flashed donor ECU, an engineer must verify five critical electrical circuits:
- Vehicle Speed Sensor (VSS — Pin 54):
06A(Transverse Mk4): Receives a discrete Hall-effect pulsed ground signal directly from transmission sensorG22on Pin 54. The C167CR uses on-chip timer capture to computevfzgandgangi.8E0(Longitudinal B6): The transmission has no physicalG22sensor. Vehicle speed is calculated by the Bosch 5.7 / 8.0 ESP module from the four ABS wheel speed sensors and broadcast across CAN bus at message ID0x280/0x288. Pin 54 is unpopulated.- Conversion Rule: When cross-flashing
06Afirmware onto an8E0ECU for use in a Mk4, the C167 hardware timer capture routine on Pin 54 activates automatically. Ensure Pin 54 from the Mk4 body harness connects to the ECU.
- Radiator Fan Control (
J293— Pins 41 & 42):06A(Transverse Mk4): Pin 42 is a low-side ground trigger to energize Fan Stage 1; Pin 41 is an input from the A/C high-pressure switch (F129) to trigger Fan Stage 2.8E0(Longitudinal B6): Pin 42 outputs a high-frequency (100 Hz to 250 Hz) Pulse-Width Modulated (PWM) command signal to the B6 solid-state dual-fan controller module.- Conversion Rule: Flashing
06A906032LPfirmware onto an8E0board switches the output transistor on Pin 42 from high-frequency PWM to simple digital on/off ground sinking, matching the Mk4J293relay module.
- Exhaust Gas Temperature Thermocouple (
G235— Pin 36):06A(AWP / AUQ): No physical thermocouple is installed. EGT is computed via the physical heat model (ATR/tabg_w). Pin 36 is unpopulated.8N0(Audi TT 225 BAM / APX): Populates an active thermocouple amplifier module (G235) mounted on the turbine housing, delivering a 0.0V–5.0V analog temperature signal into Pin 36.- Conversion Rule: An
8N0donor ECU installed in a Mk4 ignores Pin 36 once flashed with06A906032LPfirmware, reverting to the standard modeled EGT strategy.
- Internal Barometric Pressure Sensor (
DS-LDF2vs. Ambient):06A(Transverse): Relies on intake manifold MAP sensorG31(Pin 101) sampled at key-on before starter engagement to set atmospheric reference pressure P_{\text{amb}}.8E0/4B0(Longitudinal): Incorporates an internal surface-mount barometric pressure sensor (Sensata / Motorola MPX4100AP) on the internal PCB connected directly to ADC channel 7 (AN7).- Conversion Rule: Cross-flashing
06A906032LPfirmware onto an8E0hardware board continues reading ambient pressure from Pin 101 at key-on; the internal PCB sensor is simply unpolled and remains harmlessly dormant.
- Diagnostic K-Line (Pin 43) & Drivetrain CAN Bus (Pins 58 & 60):
- K-Line (Pin 43): Identical across all ME7.5 platforms. Dedicated bi-directional ISO 9141-2 / KWP2000 diagnostic bus.
- Drivetrain CAN (Pins 58 CAN-H & 60 CAN-L): Operates at strictly 500 kbps across all VAG ME7.5 platforms. Compatible with Mk4 Instrument Cluster (
J285), ABS/ASR/ESP (J104), and Airbag controllers (J234).
13.2. Master 121-Pin Cross-Reference Table#
The table below lists every functional pin across the 121-pin dual-chamber housing, comparing signal definitions across 06A Transverse (AWP/AUQ), 8E0 Longitudinal (AMB), and 8N0 High-Output (BAM):
| Pin No. | Chamber | 06A Transverse (VW Golf/Jetta AWP) | 8E0 Longitudinal (Audi A4 AMB) | 8N0 Transverse (Audi TT BAM) | Electrical Type & Notes |
|---|---|---|---|---|---|
| 1 | A | Power Ground (Cylinder Block) | Power Ground (Cylinder Block) | Power Ground (Cylinder Block) | Heavy Gauge (2.5 mm²), direct engine block ground |
| 2 | A | Power Ground (Cylinder Block) | Power Ground (Cylinder Block) | Power Ground (Cylinder Block) | Heavy Gauge (2.5 mm²), direct engine block ground |
| 3 | A | Switched 12V (Via Motronic Relay J271) | Switched 12V (Via Motronic Relay J271) | Switched 12V (Via Motronic Relay J271) | Main ECU logic power from Terminal 87 |
| 4 | A | Sensor Ground (G31, G42, G62) | Sensor Ground | Sensor Ground | Clean analog sensor ground reference |
| 5 | A | Pre-Cat O2 Sensor Heater (Z19 Return) | Pre-Cat O2 Sensor Heater Return | Pre-Cat O2 Sensor Heater Return | Low-side PWM ground switch for LSU 4.2 heater |
| 15 | A | EVAP Purge Solenoid (N80 Ground) | EVAP Purge Solenoid Ground | EVAP Purge Solenoid Ground | Low-side PWM driver |
| 21 | A | Permanent Battery 12V (Terminal 30) | Permanent Battery 12V (Terminal 30) | Permanent Battery 12V (Terminal 30) | Constant battery power for EEPROM & RAM standby |
| 33 | A | Throttle Drive EPC Potentiometer 1 (G187) | Throttle Drive Potentiometer 1 | Throttle Drive Potentiometer 1 | 0.5V–4.5V analog input from throttle body |
| 34 | A | Throttle Drive EPC Potentiometer 2 (G188) | Throttle Drive Potentiometer 2 | Throttle Drive Potentiometer 2 | 4.5V–0.5V inverse analog input (redundancy check) |
| 35 | A | Accelerator Pedal Position 1 (G79) | Accelerator Pedal Position 1 | Accelerator Pedal Position 1 | 0.5V–4.5V analog pedal input from driver |
| 36 | A | Accelerator Pedal Position 2 (G185) | Accelerator Pedal Position 2 | Physical EGT Sensor Input (G235) | In BAM: 0–5V EGT analog. In 06A/8E0: Pedal 2 |
| 37 | A | Engine Speed / Tachometer Output (G5) | Unused / CAN Broadcast | Engine Speed Output (G5) | Square-wave engine speed signal to cluster |
| 41 | A | A/C Pressure Switch / Fan Stage 2 Trigger | Unused | A/C Pressure Switch Input | Digital low-side trigger |
| 42 | A | Radiator Fan Stage 1 Relay Trigger (J293) | Radiator Fan PWM Control (Module) | Radiator Fan Relay Trigger | In 06A: Digital Ground. In 8E0: 100–250 Hz PWM |
| 43 | A | Diagnostic K-Line (OBD Pin 7) | Diagnostic K-Line (OBD Pin 7) | Diagnostic K-Line (OBD Pin 7) | Bi-directional serial communication line |
| 51 | A | Pre-Cat O2 Pump Current (Ip — LSU 4.2) | Pre-Cat O2 Pump Current (Ip) | Pre-Cat O2 Pump Current (Ip) | Wideband oxygen pump cell terminal |
| 52 | A | Pre-Cat O2 Nernst Cell (Vm — LSU 4.2) | Pre-Cat O2 Nernst Cell (Vm) | Pre-Cat O2 Nernst Cell (Vm) | Wideband oxygen measurement cell terminal |
| 54 | A | Vehicle Speed Sensor Input (G22) | Unused (Speed via CAN 0x280) | Vehicle Speed Sensor Input (G22) | Critical Discrepancy: Discrete Hall wave on 06A |
| 58 | A | Drivetrain CAN-High (500 kbps) | Drivetrain CAN-High (500 kbps) | Drivetrain CAN-High (500 kbps) | High-speed differential powertrain bus |
| 60 | A | Drivetrain CAN-Low (500 kbps) | Drivetrain CAN-Low (500 kbps) | Drivetrain CAN-Low (500 kbps) | High-speed differential powertrain bus |
| 62 | A | Switched Ignition 12V (Terminal 15) | Switched Ignition 12V (Terminal 15) | Switched Ignition 12V (Terminal 15) | Key-on wake-up signal from ignition switch |
| 63 | A | Post-Cat O2 Sensor Heater (Z28 Return) | Post-Cat O2 Sensor Heater Return | Post-Cat O2 Sensor Heater Return | Low-side PWM driver for secondary O2 heater |
| 64 | A | Diverter Valve Solenoid (N249 Ground) | Diverter Valve Solenoid Ground | Diverter Valve Solenoid Ground | Low-side switched ground driver |
| 65 | A | Fuel Pump Relay Trigger (J17 Ground) | Fuel Pump Relay Trigger Ground | Fuel Pump Relay Trigger Ground | Low-side ground switch for master fuel relay |
| 70 | A | Pre-Cat O2 Trim Resistor (Rt — LSU 4.2) | Pre-Cat O2 Trim Resistor (Rt) | Pre-Cat O2 Trim Resistor (Rt) | Factory laser-calibrated bias resistor |
| 71 | A | Pre-Cat O2 Reference Voltage (Vs — LSU) | Pre-Cat O2 Reference Voltage (Vs) | Pre-Cat O2 Reference Voltage (Vs) | 450 mV Nernst cell reference voltage |
| 82 | B | Engine Speed Sensor (G28 VR-) | Engine Speed Sensor (G28 VR-) | Engine Speed Sensor (G28 VR-) | 60-2 trigger wheel reluctance pickup negative |
| 88 | B | Fuel Injector Cylinder 1 (N30) | Fuel Injector Cylinder 1 (N30) | Fuel Injector Cylinder 1 (N30) | Low-side saturated MOSFET driver (13.5–16.0 Ω) |
| 89 | B | Fuel Injector Cylinder 2 (N31) | Fuel Injector Cylinder 2 (N31) | Fuel Injector Cylinder 2 (N31) | Low-side saturated MOSFET driver |
| 90 | B | Engine Speed Sensor (G28 VR+) | Engine Speed Sensor (G28 VR+) | Engine Speed Sensor (G28 VR+) | 60-2 trigger wheel reluctance pickup positive |
| 93 | B | Engine Coolant Temperature Sensor (G62) | Engine Coolant Temperature Sensor | Engine Coolant Temperature Sensor | NTC thermistor input (analog ADC) |
| 94 | B | Ignition Coil Cylinder 1 Trigger (N70) | Ignition Coil Cylinder 1 Trigger | Ignition Coil Cylinder 1 Trigger | 5V active high logic trigger to internal igniter |
| 95 | B | Ignition Coil Cylinder 2 Trigger (N127) | Ignition Coil Cylinder 2 Trigger | Ignition Coil Cylinder 2 Trigger | 5V active high logic trigger |
| 96 | B | Fuel Injector Cylinder 3 (N32) | Fuel Injector Cylinder 3 (N32) | Fuel Injector Cylinder 3 (N32) | Low-side saturated MOSFET driver |
| 97 | B | Fuel Injector Cylinder 4 (N33) | Fuel Injector Cylinder 4 (N33) | Fuel Injector Cylinder 4 (N33) | Low-side saturated MOSFET driver |
| 99 | B | Knock Sensor 2 Signal (G66 Ground) | Knock Sensor 2 Signal Ground | Knock Sensor 2 Signal Ground | Shielded piezoelectric accelerometer return |
| 100 | B | Knock Sensor 2 Signal (G66 Positive) | Knock Sensor 2 Signal Positive | Knock Sensor 2 Signal Positive | Piezoelectric AC voltage waveform input |
| 101 | B | Manifold Absolute Pressure Sensor (G31) | Manifold Absolute Pressure Sensor | Manifold Absolute Pressure Sensor | 0.4V–4.65V analog boost signal (DSLGRAD/DSLOFS) |
| 102 | B | Ignition Coil Cylinder 3 Trigger (N291) | Ignition Coil Cylinder 3 Trigger | Ignition Coil Cylinder 3 Trigger | 5V active high logic trigger |
| 103 | B | Ignition Coil Cylinder 4 Trigger (N292) | Ignition Coil Cylinder 4 Trigger | Ignition Coil Cylinder 4 Trigger | 5V active high logic trigger |
| 104 | B | Wastegate Solenoid (N75 Ground Return) | Wastegate Solenoid Ground Return | Wastegate Solenoid Ground Return | Dedicated N75 PWM Driver: Never reassign! |
| 106 | B | Knock Sensor 1 Signal (G61 Positive) | Knock Sensor 1 Signal Positive | Knock Sensor 1 Signal Positive | Dedicated G61 Input: Never connect actuators! |
| 107 | B | Knock Sensor 1 Signal (G61 Ground) | Knock Sensor 1 Signal Ground | Knock Sensor 1 Signal Ground | Shielded accelerometer return |
| 112 | B | Variable Camshaft Solenoid (N205 Ground) | Variable Camshaft Solenoid Ground | Variable Camshaft Solenoid Ground | Low-side PWM driver (VVT Advance) |
| 113 | B | Leak Detection Pump Solenoid (V144) | Leak Detection Pump Solenoid | Unused (No LDP on Euro BAM) | Low-side driver for evaporative reed pump |
| 115 | B | Secondary Air Solenoid (N112 Ground) | Secondary Air Solenoid Ground | Secondary Air Solenoid Ground | Low-side vacuum combivalve solenoid trigger |
| 121 | B | Switched Terminal 87 Power (Injectors) | Switched Terminal 87 Power | Switched Terminal 87 Power | Fused 12V supply for output driver flyback |
Related#
Cross-referenced on shared calibration symbols, not on subject matter — these are the chapters that touch the same maps.
- Chapter 2 — Bosch Project Taxonomy —
G235,J17,J104,J285,TABG_W,ASR - Chapter 7 — DFPM & Emissions Strategy —
Z28,Z19,J17,V144,N112,N249 - Chapter 3 — Benchmark Calibrations —
DSLGRAD,DSLOFS,G42,G31,VFZG,GANGI - Chapter 25 — Troubleshooting & Failsafes —
J271,G62,G42,G66,G61,N205 - Chapter 34 — PCB Repair & IC Pinouts —
J17,V144,N112,N249,N205,N80 - Chapter 9 — Donor ECU Conversion —
J293,G235,J104,V144,ATR,N80
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