[streetrodmuscle]

I am busy installing a 2002 Camaro 3800 series 2 engine in a Plymouth 1948. I cannot find any information on how to connect the tach wire. I am subscribing to the AllDataDIY so I have most diagrams. There is a VSS signal available on the PCM connectors (actually there are three).
C1 pin 55 is called VSS signal
C1 pin 64 is called VSS high signal
C1 pin 65 is called VSS low signal
I cannot start the engine yet, so no way to test.
Anyone who knows and like to help?:icon_lol:

I saw a listxxx. post somewhere to use a wire on the coil pack, but that specific pin E is not connected on my coil pack
Bo

 

[streetrodmuscle]

mixup?

I think I got it all mixed up. The VSS is the speed signal, not the tach pulse! :icon_cry:
So I need another tach pulse. Anybody did this?
Bo

 

[jakesq]

It looks like the ignition signal wire from the ignition module(coil module) to the PCM should give you a tach signal depending on what you tach needs for a signal. Maybe ask the tach mfg for a tip or schematic. I looked thru a bunch of diagrams and finally found all the guages and indicators work off an internal logic module (part of the cluster assy).

If you run into a dead end of this, talk to MSD. I'm pretty sure they will have some sort of pick-up for a tach pulse. Jake

 

[streetrodmuscle]

Thanks for the answer!
Yes, you are right. There is a signal coming from the ICM (coil pack) that is called "Low resolution engine speed" pin D. I found a description that this is giving a x3 pulse going to the PCM. The color of the wire is white which also seems to be GM standard for tach signals.
My tach comes from Speedhut.com and their gauges are very adaptable, so I would be surprised if it cannot correctly use this x3 pulse. I am going to investigate that now.