Park/Neutral/Reverse/Drive signal to ECM

[eric8]

The LS swap book I am reading mentions that the ECM needs to know when the vehicle is in gear or not in order to determine idle speeds, etc. However, reading the Chevrolet Performance E Rod harness instructions, it makes no mention of this signal going to the ECM. I plan on using a crate LS3 with the Chevrolet performance engine controller and harness. Any idea how the GM harness is getting this data? See here: http://paceperformance.com/files/pdf/19244807E-ROD.pdf

[BR3W CITY]

The signal is off of the Neutral safety switch, which is on the transmission portion of the harness. It can be run without (I don't use it), or can be hooked up to an aftermarket shifter or switch. Its just a contact switch.

[eric8]

So where is the neutral safety switch on the 4l60e? I guess I've read so much on this subject even I'm confused. You have the neutral/park safety switch on the factory steering column. Then if you have a truck transmission, you have a gear position switch on the drivers side of the tranny. But if you have a car 4l60e there is no switch? I am going to be running the GM Supermatic transmission controller and harness with a 4l60 or 4l70e. So you are saying the transmission controller takes this input from its harness, and then relays it to the ECU?

[truckdude239]

Mines not hooked up its not really needed

[BR3W CITY]

Originally Posted by eric8

So where is the neutral safety switch on the 4l60e? I guess I've read so much on this subject even I'm confused. You have the neutral/park safety switch on the factory steering column. Then if you have a truck transmission, you have a gear position switch on the drivers side of the tranny. But if you have a car 4l60e there is no switch? I am going to be running the GM Supermatic transmission controller and harness with a 4l60 or 4l70e. So you are saying the transmission controller takes this input from its harness, and then relays it to the ECU?

You only have the NSS on the steering column if you had a column shift vehicle. The same vehicle equipped with a floor shift would have one in the shifter assembly, or could very well have one on the Range indicator (the second plug on late model electronic trans harnesses).

You don't NEED any of them, but you only want to run 1. Because its just a contact switch, it can be mounted anywhere that connects when in park. You could put it on a toggle switch if you REALLY wanted to, but it would just be weird and probably a recipe for headaches.

on the range selector


Aftermarket NSS for custom shifters


And I couldnt' find the column shift one, but they all wire up the same. You can use anything you want to make the connection.