• Top Street Performance 2014 and Later GM LT L86/L83 Engine and Standard Transmission Wiring Harness
  • Top Street Performance 2014 and Later GM LT L86/L83 Engine and Standard Transmission Wiring Harness - front view
  • Top Street Performance 2014 and Later GM LT L86/L83 Engine and Standard Transmission Wiring Harness - side view
  • Top Street Performance 2014 and Later GM LT L86/L83 Engine and Standard Transmission Wiring Harness - close-up
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Top Street Performance

2014 and Later GM LT L86/L83 Engine and Standard Transmission Wiring Harness

2014 and Later GM LT L86/L83 Engine and Standard Transmission Wiring Harness

SKU: WH1222

$660.00
$660.00 $750.00
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In stock

Top Street Performance (TSP) is committed to providing high-quality performance parts while complying with emissions regulations. This product is designed for use on vehicles that comply with federal emissions regulations. It is the customer’s responsibility to verify that this part is legal for use in their state or local jurisdiction. Check with your local emissions authority before purchasing.

Product Details

Features

  • Standalone DBW engine harness for 2014+ L86/L83 engines with T56 manual trans
  • Swap-only combination — no factory GM vehicle used this pairing
  • Includes fuse/relay box, sensor wiring, fuel pump/fan control, OBD2
  • Requires GM connectors 28604913 (driver) and 28605173 (passenger) to complete install

Description

2014 and Later GM LT L86/L83 Engine and Standard Transmission Wiring Harness

This 2014 and Later GM LT L86/L83 Engine and Standard Transmission Wiring Harness is built for standalone Drive-by-Wire engine management with standard transmission. The harness integrates the fuse/relay box, sensor connectors, engine control wiring, fuel pump control, fan control, OBD2 connection, and supporting outputs needed for a clean LS/LT engine control installation.

Use this harness when the engine code, throttle type, transmission connector, ECU strategy, and sensor layout match the compatibility section. Confirm transmission pin count, pedal and throttle body requirements, oxygen sensor layout, MAP/MAF connections, and power/ground routing before installation.

Specs

ThrottleDrive-by-Wire
Harness LengthStandard
Fuse BlockIncluded
QuantitySold as a Kit
Included
  • Fuse/Relay Box and Plugs
  • Fuel Pump Control
  • Fan Controls
  • Check Engine Light
  • Speedometer
  • Tachometer
  • OBD2
  • Accelerator Pedal and Throttle Body Control
  • MAF Sensor
  • MAP Sensor
  • Engine Coolant Temp Sensor
  • Alternator Control
  • (2) Upstream Oxygen Sensors
  • Crankshaft Position
  • Camshaft Position
  • Coil Packs
  • Knock Sensors
Connections
  • GM28604913 (Driver Side) – Needed to Complete Installation
  • GM28605173 (Passenger Side) – Needed to Complete Installation
Not Included
  • Fuel Injectors
  • Fuel Injector Sub Harnesses

Engine Fitment

COMPATIBLE WITH
2014 and later LT engines*
*Fits L86 and L83 engines with T56 manual transmissions.

NOTES
• This harness is intended for engine swap applications pairing an L86/L83 engine with an aftermarket T56 manual transmission. No factory GM vehicle was equipped with this engine/transmission combination from the factory.
This harness is wired for a 3-wire fuel pressure sensor.
• Confirm your fuel pressure sensor uses a 3-wire connector before installation, as 4-wire and other sensor styles are not compatible without modification.

COMMON VEHICLE APPLICATIONS
LS/LT engine swap applications using an L86/L83 engine paired with a T56 manual transmission — not a factory-original configuration for any GM truck or SUV

Q&A

What engines and transmissions is this harness compatible with?
This standalone wiring harness is designed for 2014-and-later GM Gen V L83 5.3L and L86 6.2L engines paired with a T56 manual transmission.

Is this a factory GM combination?
No. GM did not offer any production vehicle with an L83 or L86 engine paired with a T56 manual transmission. This harness is designed specifically for custom engine swap applications.

Does this include a PCM/ECM?
No. This is a standalone engine wiring harness and does not include a PCM/ECM. A compatible PCM/ECM programmed for your specific engine configuration is required.

What connectors do I need to complete the installation?
This harness requires GM connector 28604913 (driver side) and GM connector 28605173 (passenger side) to complete the installation. These connectors are not included and must be purchased separately.

Does this include fuel injectors or injector sub-harnesses?
No. Fuel injectors and fuel injector sub-harnesses are not included with this harness.

What's included in this harness kit?
This harness includes wiring for the fuse/relay box, fuel pump control, electric fan controls, OBD2 diagnostic port, MAF sensor, MAP sensor, engine coolant temperature sensor, alternator control, two upstream oxygen sensors, crankshaft position sensor, camshaft position sensor, coil packs, and knock sensors.

Does this include the throttle body or accelerator pedal?
No. The throttle body and accelerator pedal are not included and must be purchased separately.

Emissions Notice

This product does not affect vehicle emissions and is not subject to emissions compliance regulations.