97 Silverado remote start

Where is the best spot to pick up a tach signal for a remote start.(97 Chev Silverado 5.7 Vortec) I tried the white wire at the coil and the system works, but the check engine light comes on when starting with remote. If you start with the key the light doesn't come on. I'm assuming that this is my problem. The code is for the torque convertor. Does anyone know what wire off the PCM or fuel injector wire I can use??? Thanks for any input.

you need to power up the second ignition on the truck should be a white wire right next to the yellow starter wire in the harness under the dash. it needs to be connected as a true ignition so all the way thru the start cycle.

Thanks, I'll try that.

glad to help let us know if that cured your problem.