1.8T MK4 Wire Tucked Complete Engine Harness Wideband ECU's only AWP, AWW, BEA, BAM -
Introducing the Carrot Top Tuning 1.8T VW MK4 Engine Tucked Harness - Now available in three convenient stages for your customization needs:
Stage 1: Our Stage 1 kit comprises the essential ECU 40 pin engine loom with a quick-connect feature, ensuring seamless installation and removal. Can be utilized with the OE 81 pin side harness.
Stage 2: Elevate your wiring setup with our Stage 2 package, which includes the 40 Pin main loom and the 81 pin connector. This connector houses critical components such as the O2 sensor, Main ECU Relay, Fuel Pump Relay, Starter Signal, Reverse Lights, Mass Airflow Sensor, and Coil power input, offering a comprehensive solution for your engine harness needs.
Stage 3 (In Development): Stage 3, currently in development, will take your engine bay aesthetics to the next level by enabling the relocation of the body harness for a cleaner appearance.
Our design philosophy prioritizes versatility, catering to both dedicated track cars and daily drivers. Crafted with PTFE Teflon high-temperature resistant wiring, our harness can withstand extreme temperature fluctuations, ranging from -90 °C to 260 °C. Each connector is meticulously labeled for easy identification and component removal without disconnecting the main loom from the engine. The inclusion of a milspec quick connect on the frame rail simplifies the installation process.
Furthermore, our harness features an integrated Fuel Pump relay for additional AUX Fuel Pump applications, ideal for fuel-hungry setups or surge tanks within the engine bay. You'll also find a removable partial coil expansion harness, injector connectors, N75 (for manual boost controller applications), and MAF (for maffless setups) to streamline your engine bay by eliminating unnecessary connections. Additionally, we provide a secondary wideband hookup at the OE location beneath the car. The top connector conveniently links to an AFR gauge, eliminating the need for extra wiring through the chassis.
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.
Product Disclaimer:
Emissions Equipment Tampering Warning: In many states, tampering with your vehicle’s emissions equipment is unlawful. Our products are designed and sold for sanctioned off-road/competition non-emissions controlled vehicles only and may never be used on a public road or highway.
Using our products for street/road use on public roads or highways is prohibited by law unless a specific regulatory exemption exists (more information can be found on the SEMA Action Network website www.semasan.com/emissions for state-by-state details in the USA).
CARB-Restricted Areas: CARB-Restricted products, will not be shipped to state of California under any circumstatences.
Official Air Resource Board Link: ARB State Adoption Link
Customer Responsibility: It is the responsibility of the installer and/or user of this product to ensure compliance with all applicable local and federal laws and regulations. Please check with your local vehicle authority before purchasing, using, or installing any of our products.
By proceeding with the purchase and use of our products, customers affirm their commitment to adhere to the terms outlined in this comprehensive product disclaimer. We reserve the right to update this disclaimer as necessary.
