457G w/ 2001 Bravada S10 Data Bus Problem

I have a 2001 Oldsmobile Bravada 4.3L S10 which is the same for all 1999-2001 models, the 1999-2001 GMC Jimmy is very similar, and even the 1999-2000 Envoy S10 is similar, and close to all 1998-2005 Chevy Blazers and S10 trucks(GM is still selling these!). Basically these vehicles are all brothers; they each have their own distinctions electrically but are essentially the same trucks. It is my understanding that all these late model S10 variants have data bus systems _simular_ to the newer GM trucks (Trailblazer/Envoy), just not as mature. Now I have been working on my Bravada for some time, and using my CS-2011 RS has been a dream, I started with the DEI 555L for passkey II which worked fine, but I like to try new things, and I did a little research and decided to try the 457G as it included a few features that interested me. I was primarily interested in passkey disarm through the OBD-II data bus, all handled through a PIC microcontroller, and all very interesting! The 457G handles passkey-II fine (once you program the unit and so long as it doesn't loose power) however on my application the door locks, the trunk, and the horn do not function. The CS-2011 is operating properly, and the 457G is communicating on the data bus (verified with oscilloscope, i am a weekend EE warrior) however my vehicle does not respond. I have also circumvented using the dome light and door trigger outputs on the 457G as the CS-2011 handles door triggers and dome lights efficiently on its own, but have connected them to test and still no differences. Also to note, for the 457G i have taken the power, ground and data directly from the OBD-II plug, and have diode isolated the ground. My question is, has anyone had any luck with the 457G and the features I mention on an application simular to those I outlined above? DEI states that certain features are unavailable on some models, but the 2001 Bravada is listed to work as well as other late model S10 variants, all of which have an updated data bus and locks which should operate on this bus. I know I could get a different data bus module, but this module is communicating with my vehicle, it just doesn't want to do what it’s told. Anyone with a contact at DEI want to ask them about my bad Bravada? Thanks everyone! Michael

This is what DEI says about this module for this vehicle: Can use the 457GW to bypass the Passlock II, but it will not control the door locks on this model year. What you have to do is wire in the door locks directly from the CS harness to the door lock wires at the BCM and you will need relays or a polarity inverter to change to (+) pulse.Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA

Hey XS, the Bravada is a databus vehicle, it's just the door locks are not controlled via databus only the Passlock II is via databus.Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA

Thanks, I was unable to find that information, so let me be restate my post... While the 457G is communicating on my vehicles data bus, my vehicle is NOT EQUIPED to handle data bus requests for operation of the locks, the horn, and the hatch. I would also assume that operations of the HVAC for defrost, heat, and heated seats as advertised for this unit by DEI are also non-functional. Therefore the 457G is ONLY capable of negotiating passkey-II communications while performing RS in this vehicle, albeit without splicing into the ignitions passkey resistance wiring. Therefore the better solution from DEI for this particular late model S10 is a 555L as it never needs to be reset due to power failure, it’s a turnkey solution. I am glad that I left all my wiring intact for the door locks as I will be removing the 457G.     Now if this vehicle can do passkey communications through the data bus there is a good chance that it can do more, I am interested in finding this information. Is there a different data bus module which can be confirmed to perform similar functions for this vehicle? Is the communications within this vehicles data bus undocumented? I have factory shop manuals and have not recognized any such information. Is there any data bus information available for this vehicle? Michael