Wiring e9x LS Swap Gas Pedal

This has to be one of the top three questions and problems people run into doing the swap.  It is due to multiple issues including wrong throttle body, wiring issues, etc.  We will go over a lot of the common problems.

Throttle Body Selection:

Hands down of the best throttle bodies is a genuine LS3 throttle body GM part #12605109.

These can be sourced from several online retailers.  It is one of the models Holley has built-in support for on the Terminator X Max. It has been widely tested and used.

Terminator X Wiring Harness:

Holley Part # 558-406 which is for 6 pin throttle bodies, like the LS3 discussed above.  Holley also offers a 8 pin harness for early truck throttle bodies but we recommend not using it since you will most likely need to re-pin the connector for the commonly used throttle bodies. The wiring can be sensitive and should have as few of splices, connections, etc as possible.

How to Connect e9x Wiring Harness to Terminator X for use with Stock Gas Pedal:

Below is a list for how to wire the DBW harness to preexisting BMW wiring in the engine bay to use the factory accelerator pedal.  You will notice the list uses pin numbers for the BMW wiring to splice, this is due BMW using different wire colors across models and years.  

And here is the Holley 558-406 Wiring Diagram for reference:

If you have not read our Terminator X Wiring Guide, the most important takeaway is DO NOT CONNECT THE RED/WHITE WIRE FROM THE DBW HARNESS TO IGNITION 12V+ POWER.  It must either be connected to brake switch signal or left disconnected (you should only consider doing this for track use vehicles as this wire is for a safety feature).

Another great option is to use a connector so cutting of the Holley DBW harness is not required.  This prevents issues with bad connections (very common due to poor wire splicing). We offer this a kit with two options, crimp pins or premade with pigtail. CHECK OUT THE KIT HERE!

Please contact us with any question you may have!

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