labwork Wiring Harness T56 For 1999–2003 DBC LS1 or Non-Electric Tran 4.8 5.3 6.0L

Key Features & Technical Advantages

• Premium OE Quality Plus: Engineered to meet or exceed original equipment standards. Every harness undergoes a rigorous quality control check prior to shipment to ensure flawless electrical performance and long-term durability.

• Extended Layout for Easy PCM Mounting: Built with convenience in mind, this harness features an added 36 inches of length, providing ample clearance to mount your powertrain control module (PCM/Computer) safely under the dashboard.

• Sliding Firewall Grommet: Equipped with a high-quality rubber grommet that slides freely along the harness, allowing you to adjust it perfectly to your vehicle's specific firewall hole and desired mounting position.

• Standard GM Color Coding: Strictly utilizes factory GM color codes for clear circuit identification. This greatly simplifies installation, custom routing, and future troubleshooting (unlike many competitors who do not use factory color schemes).

• Maximum Thermal & Mechanical Protection: All circuits routed through high-heat areas are protected by a rugged 1200°F fiberglass braid sleeve. Heavy-duty, reinforced ring terminals are used throughout to guarantee reliable grounding.

• Factory CPA Locks: All connectors feature integrated Factory CPA (Connector Position Assurance) locks, preventing plugs from vibrating loose under intense driving or off-road conditions.

• Complete Dash Connections: Comes pre-wired with all essential dashboard leads, including connections for the Speedometer, Tachometer, Park/Neutral switch, Torque Converter Clutch (TCC), Malfunction Indicator Light (MIL), and a built-in DLC (OBD2) diagnostic port.

Crucial Fitment & Compatibility Notice

Please Read Before Purchasing: This is a universal standalone conversion harness and does not have specific vehicle-specific application guide data. Due to recent fitment issues reported in aftermarket installations, please verify that your exact engine and transmission configuration matches the requirements below:

Official Application Requirements

• Compatible Engine Years: 1999, 2000, 2001, 2002, 2003

• Compatible Engine Displacements: GM Gen III LS-Based V8 (4.8L, 5.3L, 6.0L Vortec / LS1 variants)

• Throttle Configuration: Must be a Mechanical Throttle Body (Drive-by-Cable / Cable Operated Only)

• Transmission Compatibility: Designed exclusively for T56 6-Speed Manual Transmissions

• Fuel Injector Connector Type: EV1 Injector Plugs

⚠️ Non-Compatibility & Exclusions

• NO Flex Fuel Sensor Plug: This harness does not include a connector or circuit for a Flex Fuel / Ethanol sensor.

• NOT Compatible with Electronic Throttle (Drive-by-Wire) systems.

• NOT Compatible with early 1997–1998 LS1 engines or 2004-and-newer LS/Vortec platforms.

• NOT Compatible with automatic transmissions (such as 4L60E or 4L80E).

Product Specifications

• Part Type: Automotive Standalone Engine Wiring Harness

• Injector Interface: EV1

• Throttle Style: Drive-by-Cable (DBC)

• Wiring Sleeve: High-Temperature Fiberglass Braid & Flame-Retardant Loom

• Condition: 100% Brand New

Package Includes

• 1 x Complete Standalone Wiring Harness Assembly

Installation & Maintenance Notes

• Installation Manual Is NOT Included: This product does not ship with step-by-step documentation.

• Professional Installation Highly Recommended: Due to the complexity of powertrain wiring swaps and PCM tuning adjustments, it is strongly advised to have this component installed by an experienced automotive wiring specialist or custom tuning shop. Incorrect DIY wiring can lead to short circuits or component damage.