*** IMPORTANT NOTE: Order processing can take up to 3 business days. Shipping timeframes start after the order processing has been completed. ***
Stage 1: This entry-level option includes the essential 40-pin ECU engine harness. Designed for compatibility with the factory 81-pin side harness, it's ideal for those looking to clean up their engine bay while retaining OEM-side wiring.
Stage 2: The Stage 2 setup includes both the 40-pin engine harness and an 81-pin interface harness. This extended configuration incorporates critical circuits including the O2 sensor, Main ECU Relay, Fuel Pump Relay, Starter Signal, Reverse Lights, Mass Airflow Sensor, and Coil Power Input. It's a complete solution for more extensive rewiring needs.
Built for Track or Street Whether you're building a dedicated track car or maintaining a reliable daily, this harness is constructed using high-temp PTFE Teflon wire, rated for environments from -90 °C to 260 °C. Each connector is clearly labeled for straightforward installation and serviceability, allowing engine-side work without removing the entire harness.
Since VW decided to discontinue factory ECU connectors and pins, we partnered with TE Connectivity to source all genuine ECU pins and implement a new-age, modern sealed-leavy-seal connector. It not only looks cleaner and more compact but also offers improved performance and long-term availability—ensuring we can continue building and supporting these harnesses reliably.
The loom includes an integrated Fuel Pump Relay to support auxiliary pump setups—ideal for surge tanks or high-demand fuel systems. You’ll also find a detachable coil harness section, injector plugs, N75 wiring for those still running boost control, and a MAF lead for setups that retain it.
A dedicated secondary wideband input is placed in the OEM underbody location, with the top-side connector ready to feed directly to your AFR gauge—no need to run wires through the cabin.
Connector Abbreviation Overview:
40 Pin ECU Connector: Ignition Coils (1-4) INJ1, INJ2, INJ3, INJ4 (Fuel Injectors) VSS (Vehicle Speed Sensor) N75 (Boost Control Solenoid - Resistor required if removed) IAT (Intake Air Temp Sensor) BT (Throttle Body) OIL (Oil Pressure Switch) CRANK (Crankshaft Position Sensor) MAP (Boost Pressure Sensor - Choose stock location or under the intake manifold, one must be used) ECT (Coolant Temp Sensor) KS2 (Knock Sensor Cyl 3-4) KS1 (Knock Sensor Cyl 1-2) CAM (Camshaft Position Sensor) COILS (Ignition Coil Expansion Harness) N249 (Resistors Included) COIL 12V (Ignition Coil Power output) CHASSIS (Multi-Pin Connector Near the Battery in factory location) GROUND (Chassis Ground)
81 Pin ECU Connector: N112, N80 (Resistors Included) ECU (Main ECU Relay) FP AUX (Additional Fuel Pump Relay) Wideband (Main O2 Sensor - 6 Pin connector, suitable for AFR gauge hookup, LSU 4.9 O2 Sensor Compatible Gauges) FP 12V IN (12V+ Ignition Source for powering the AUX fuel pump - Optional, run the expansion harness down to the terminals inside the car, connects to 75xx Yellow Terminal or the Battery direct) FP 12V OUT (12+ Ignition Output for the AUX Fuel pump, connects directly to the positive terminal on the AUX pump - Optional) GROUND (Chassis Ground) ST (Starter Signal) REV (Reverse Lights) MAF (Mass Airflow Sensor) COIL 12V (Ignition Coil Power input) O2 Sensor - Main ECU O2 sensor OE sensor should be used. O2 AUX - Secondary O2 sensor for an AFR gauge (optional)
***PLEASE NOTE: THIS HARNESS IS FOR WIDEBAND ECU'S ONLY, IF YOU HAVE AN AWD, AMU, APX ENGINE CODE YOU WILL NEED AN AWP, OR AWW ECU TO FUNCTION CORRECTLY. Version 2 does not include a firewall disconnect, we have removed it to prevent connection issue and shielding issues for Crank, and Knock Sensors.
In some instances with some ECU's you may observe intermittent open circuit ghost codes for ignition coils, you must have your tuner remove these codes to clear the CEL. The codes do not affect performance of the vehicle, or the harness.
Exceptional quality,I ordered The wrong part for my vehicle and the return process was super easy. A member of the company even helped me pick out the right parts for my car over the phone!
H
Hunter Blaauwbroek
Looks great, works great, guy is always helpful
harness makes it look like a new car, total upgrade
Choosing a selection results in a full page refresh.
