cadillac cts viper 5701 rs issue

I installed a viper 5701 into a 2007 cadillac CTS. Everything seems to be working fine, but the remote start does not fully engage on the first attempt. It always works fine and starts the vehicle when the remote start makes the second attempt, but on the first attempt the 5701 disengages before the car starts. I tried lengthening the crank time, but that did not make a difference. The bypass interface is the Viper 1700/G1. I have the correct tach wire, and the tach learn routine registers properly. I changed the tach jumper on the 5701 brain to the more sensitive setting. I tried both the tach and smart tach settings, but it still does the same thing. Any suggestions?bzzzzttttt

Have you tried current sensing? Your tach signal may be strong enough to program (when the car is running already) but may be weak during cranking.

No I haven't. I'll give that a shot when I get the car back in. Thanks.bzzzzttttt