Modifying OBD-II systems

[Todd Israels]

At 02:31 PM 5/13/99 -0500, you wrote:
>>Date: Wed, 12 May 1999 10:55:12 -0400
>>From: Bill Shaw <bshaw at connix.com>
>>Subject: Modifying OBD-II systems
>>
>>Hi,
>>
>>As I understand it,  OBD-II is more difficult to hack then the pre-OBD-II
>>systems.  Has anyone on the list worked around the security and
>>successfully hacked their OBD-II system?  What problems did you have in
>>doing so?  Did you need any special equipment? I'd love to hear any OBD-II
>>success stories.
>>
>>Thanks,
>>Bill
>>
>
>Bill,
>
>No, OBD-II systems in many ways are actually easier than their OBD-I
>counter-parts...  The goal of OBD-II isn't to make it more difficult to
>tune, modify, or monitor, instead, the goal is to actually (in many
>ways) make it easier -- making it more standard across different
>manufacturers...  There is an increase in device [sensor] performance and
>functionality monitoring within the OBD-II PCM's and this is where the
>common misconception comes about...  This enhanced monitoring of
>sensors has caused problems for people who do aftermarket changes,
>since it may set trouble codes...
>
>What this means is that for even simple changes and modifications, it
>may be necessary to do either tuning changes in the PCM or change the
>"error detection" ranges within the PCM...  However, it is good to
>do this tighter, more strengent testing, because you can detect problems
>quicker and track them easier to their source...
>
>Unfortunately, I can't give any details about how to hack, modify,
>or otherwise change OBD-II computers, because of my job...  But I can
>rank the difficulty level...  On a scale of 1 to 10 with 1 being stupidy
>simple and 10 being practically impossible, I'd give it about a 3...
>
>Good luck with it...
>Donald
>
>

	Without causing any trouble is it possible to read the current VE table
and replace values in the table through the ADL interface?  From what I
have heard from dealer tecs a new VE table or even operational program for
the PCM but they are unaware of being able to read this info, but then they
dont need to?
	thanks for any info you can give	
						Todd Israels