Gen 4 (58x) 6L80 / 6L90 transmission
This show quality wiring harness is for use with any Gen 4 (58x) LSx engine. This wiring harness may be used with LS2, LS3, or LS7 car style engines, or Vortec (4.8L, 5.3L, 6.0L, 6.2L) truck style engines - mated with a 6L80 or 6L90 transmission.
The depicted engine computer (ECM) and transmission computer (TCM) are NOT included. A reconditioned ECM (with project specific programming) may be ADDED to your purchase using the dropdown menu options.
If you select the ECM option, a matching Accelerator Pedal (APP) is also included. Also, for compatibility reasons a Truck style throttle body may need to be used.
The 6L80 / 6L90 TCM is INSIDE the transmission oil pan. If you would like your TCM programmed for your specific project, you would need to ship the TCM to us (please email for instructions).
*** A modified engine will likely require additional custom programming (not included) for optimal performance and drivability ***
The main trunk of the wiring harness - from the back of the Intake Manifold to the ECM - is approximately 48 inches in length (4 feet). This harness length allows the ECM to be mounted inside the vehicle occupant compartment, but it could also be mounted within the engine compartment if so desired. An OEM grade Firewall Grommet is incorporated into the construction of each wiring harness, and may be positioned (slid) to any location on the main trunk length.
The wiring harness includes a Powertrain Control Relay (isolation relay) and a Fuel Pump Relay. The electric fan "trigger wires" are labeled, but would need to be wired into your relay(s). A prewired Fan Relay is optional at an additional cost - see the related dropdown option. All connections are clearly labeled, and general instructions are provided.
Please choose very carefully from all of the dropdown options. If you are uncertain about an option, please email us BEFORE ordering, for a more detailed explanation of the option. Any returned Powertrain Control System would be subject to a restocking fee - see our Terms & Conditions page.