I have installed a shock sensor that works with the existing factory alarm. It works great. I am now looking to add remote start and window close. I have a document that shows the wire info on the BCM. I have found devices that will do what I want, but I hear there is something else I need to add for the PASSLOCK feature. The document that I have says "see document 1603 for remote start interface information." does any one know where to find this info? I think this might have something to do with the PCM.

I have installed a shock sensor that works with the existing factory alarm. It works great. I am now looking to add remote start and window close. I have a document that shows the wire info on the BCM. I have found devices that will do what I want, but I hear there is something else I need to add for the PASSLOCK feature. The document that I have says "see document 1603 for remote start interface information." does any one know where to find this info? I think this might have something to do with the PCM.

Sounds like you need to contact someone for document 1603. The passlock system is the anti-theft system used on the H3. It is controlled by the BCM, with inputs from the ignition switch.
Primarily if you attempt to turn the lock cylinder without a key inserted the BCM will not allow the vehicle to start. If the BCM reads the correct voltage at the passlock sensor (inside the ignition switch), it will send a password to the PCM. If this signal is not received by the CM, the fuel injectors are shut off and the vehicle will stall immediately.

Doccument 1603 is the directed sheet on how to manually bypass passlock systems using a meter and appropriate resistors. Skip this and simply get yourself a directed 556L module that is a very straightforward interface that basically learns the needed resistance to bypass the Passlock via the databus. It then retansmits the propoer resistance each time the remote start is used. This module is small, cheap, and very easy to install. However, before adding a remote start to the existing key fob, condsider that you will not have the best range for starting the vehicle, and, after you have remotely started the vehicle, you will not be able to use the oem fob to lock/unlock while the truck is running.