Painless LS Harness - 07+ GEN IV LS3

This harness is standalone and is not intended to replace the OEM engine wiring.  Standalone harnesses are intended to run the designated engine & transmission only, generally when swapped into another vehicle.  

This harness is designed for use on any 2007 and up LS3 with throttle by wire. It uses the factory ECM & TCM and will operate engines with or without variable valve timing (VVT) and active fuel management (displacement on demand or DOD). This harness does not support flex fuel operation. Included with this harness is a 10 circuit weatherproof fuse block & mounting bracket, GM color coded wires with labels, and all the required terminals and connectors for easy installation. 

This standard length harness allows four feet from the back of the intake manifold to where the fuseblock and ECM mount. Perfect for those that plan to mount these components under the dash or in the glove box.

This harness also requires the following mating parts; ECM #12597121 or #12612384 ; TCM #24234503; Accelerator pedal #25832864 or #25835421.

This kit includes:

1. All new fuel injection harness with OEM fitment connectors and harness breakouts
2. OBDII connector, mounting bracket and check engine light
3. Rubber grommet
4. Mounting hardware

We recommend checking the online manual for the full list of required mating parts prior to ordering.  

MANUAL