Expanding on our Transmission Control options from Holley EFI. This new harness 558-455 from Holley EFI provides plug and play transmission control for the 2009+ GM 4L60 when used with a Dominator ECU. The 2009+ GM 4L60E contains an internal turbine speed sensor, which was not on the previous model year transmissions. Additionally, the valve body range selector is wired and controlled differently from the ECU.

Features

• 554-128 is a device that allows for an ECU input to be safely connected directly to the +12V side of the transbrake solenoid. This device protects the ECU input from damaging flyback voltage which occurs when the transbrake is released