Letter Re: Disabling OnStar Vehicular Tracking/Communication Systems, and EMP Protection

I have two somewhat related questions:
1.) Can the OnStar [tracking/communications] system on General Motors vehicles be TOTALLY turned off by an owner? If so, how? And if so, is a professional recommended to do the work? I envision the possibility of the Powers That Be (PTB) simultaneously turning off engines of all OnStar vehicles to create massive chaos if it supports their plan.

2.) If we experience an EMP event, can we carry a spare computer module in protective casing and just replace module in our vehicle and we are off and running again? If so, what is the proper procedure? If question is off base or not possible… What can we do? (Affordably) – Robbie in Va.

JWR Replies: 1.) From what I’ve read in Usenet forums, the shutdown feature was considered during OnStar’s design phase but was never implemented, due to liability issues. OnStar does indeed, however, provide vehicle GPS tracking to assist police in the location of a stolen OnStar-equipped vehicle.

Conceivably, a situation might arise wherein you would want to disable OnStar. (See: http://whats.all.this.brouhaha.com/?p=132 ) The only way to be sure that you are completely disconnecting it from power is to disconnect the cables from the OnStar module itself. Any layman can do this. The hard part is finding the box. Typically, the OnStar modules are hidden are in the trunk–often next to the spare tire, such as in Cadillacs.  See: http://www.cadillacfaq.com/faq/answers/onstardisable/).  The location will vary, depending on the make/model of your GM vehicle. I suspect that you cannot simply remove a fuse from your vehicle’s fuse holder array, because given the evil genius of GM’s design engineers there are probably other components–possibly essential components–that are downstream of that same fuse. (But I may be wrong. One nice thing about this blog: I’m sure that someone more knowledgeable will e-mail me within hours if I post something incorrect about anything.)

OBTW, here is an old trick that dates back to the days when car alarms were not wired into a vehicle wiring harness upstream of the fuse box: So that you can be ready to remove a fuse at a moment’s notice, one useful technique is to attach a small dimension “zip”-type plastic cable tie around the middle of a modern plastic fuse (between the fuse’s “legs”, or in the case of traditional tubular glass fuses, underneath the entire length of the fuse. That way all that you have to do is open the fuse box and jerk on the protruding cable tie–no fumbling around with a flashlight, trying to remember which is the correct fuse to pull.

On a related note, (purely for academic research, mind you) for those of you with a penchant for hacking, you can tap into your GM vehicle’s OnStar RS-232 GPS data. See: http://members.cox.net/onstar/  You can also hack into the OnStar communications module for Bluetooth. 😉 See: http://www.hackaday.com/entry/1234000170038047/

2.) Yes, a spare electronic ignition “computer” can be purchased and padded up thoroughly and carried in an ammo can or a biscuit tin. (Either will act as an effective Faraday cage.) But keep in mind that many vehicles made since the 1980s also have electronic fuel injection, which will have its own little microchip CPU.  Ask your local car mechanic–preferably one at a factory-associated dealership–for details about the ignition and fuel injection system of your particular make/model/year of vehicle.