Originally Posted by
soundengineer
today I added an Autometer "Shift-Lite" to my 2001 Camaro.
Normally you purchase "Pills" that are rated for a certain RPM(they are a certain Ohm resistance which correlates to a specific RPM for the light)
I went a slightly different route..
I made it an always on style light that comes on when you connect the ground by means of a "sink-to-ground" in the PCM
I took the Wires that the Pills normally connect to and connected them together so that there is no resistance...0 ohms = 0 rpm = always on
on the LS1 PCM, RED Connector, Pin #47 (On a Manual Transmission Only) is a sink to ground that is operated by a set of parameters in the PCM File(which can be set in the tune)
there is a wire for rpm on the light as well...for when you use the pills...
I connected it to the RED Connector Pin # 10 on the PCM because it is the RPM wire, so atleast it is seeing the RPM signal it is looking for.
In the tune you can command the shift light to come on by changing the values in the tables inside the red box in my image attachment below (this is from my 2001 Camaro..with a RTT OS...the table exists in all stock OS's as well..)
I cannot guarantee that this is the same on all PCM's... but it will work on any 99-02 LS1 based PCM with a Manual Transmission
do not attempt to do this on an automatic transmission vehicle, the pin 47 on an Auto is the control for the 2-3 shift solenoid