fgollatz
05-21-2010, 03:41 AM
I swapped a 2005 LQ4 into a G-Body. I'm receiving DTC P0654. I've looked up the code and found it to be Engine RPM Output Circuit. I tried hooking up the tach wire from the ECU to my aftermarket tach but it did not work. I even used the companies tach module with no success. I now have the wire just taped off and connected to nothing. I got the tach working by connecting one of the coil grounds to the tach and that seems to be working perfectly. I just want to know why the PCM keeps throwing the code and how to hook it up properly to stop it. I came across this link but have not tried it yet. (http://www.lt1swap.com/pictures/tach_circuit_fix.jpg)
Any ideas?
Any ideas?