GMC Repair: TACH CONNECTION, connector c2, scan tool

Question
PLEASE ,CAN YOU TELL ME HOW TO FIND THE TACH CONNECTION ON A 2002 SONOMA.I HAVE CHECKED THE PCM CONNECTIONS AND THERE IS TO BE A 32 PIN PLUG AND #20 PIN WAS TO BE FOR THE RED TACH WIRE I AM LOOKING FOR.  THANK YOU

Answer
Hi
according to my information the engine speed is sent to the IPC (cluster) from the PCM on Ckt. 121, which is a white wire on PCM connector C2 terminal 10. It is on IPC connector Terminal A3.
Should be pretty easy to diagnose if you have access to a scan tool, you can plug it in and see if the PCM is sending out an RPM signal that will be able to be seen by the scan tool. If SO it is either the wire to the IPC or the IPC.
IF NOT it is the PCM.