frisbee91

Somehow, I had never heard of the On Board Computer (OBC) hack. I didn't know that my '99 had the computer built in. Furthermore, I didn't know that my Durametric could turn it on. I just needed Version 6 of the Durametric software.

In case anyone is in the dark (like I was), ALL 996's from '99-2001 came with the OBC built into the dash, but it was an option to have it enabled, and to have the 4th stalk to control it. I believe it became a standard feature in later models.

I enabled the OBC yesterday with my Durametric. Took about 5 minutes, mostly to boot up my computer. Dealers can also enable this feature.

Rather than add the 4th stalk (which costs about $325) I'm just going to add a dash button to cycle through and select the various optons.

I have two questions for anyone who has done this:

1. If you are not installing the 4th stalk, do you need to remove the steering wheel to remove the instrument panel and get at the connector there? The DIY is unclear on this.

2. I know many people use the footwell light switch to control the OBC. Has anyone removed the graphics from a standard switch (such as the Targa switch) and replaced them with custom graphics?

Footwell light switch:


Targa Switch:


Custom Switch????


I'm planning to follow the DIYs at Renntech HERE and HERE and at Pelican . There have also been some threads on Rennlist, but somehow I missed them. There is also a PDF version of a DIY, in case anyone wants more info.

alpine003

Thanks for the info. This is an Easter egg I did not know about.

function12

I don't know about the OBDII stuff but I do know about those switches. They are all momentary contact switches. So, they might work great for cycling through a list or selecting an item but you will need a relay to turn anything off or on.
I used the footwell for lidar jammers and the targa for my garage door opener when I had a 996.

BAD.TAG

Frisbee, are you talking about accessing OBD codes via the dash or HVAC or enabling stuff like Avg MPG/DTE etc ?

I have a 2003 and would love to access OBD info on the fly

frisbee91

Nope, not OBD. OBC=on board computer. In the '99 OBC you can access outside temperature, speed gong alarm, average MPG, average speed, and range remaining on fuel.

OBD is on-board diagnostics, for emissions and maintenance.

Freakhead

Subscribed! Very interested in this. ( Going to do spoiler switch relocate and garage door switch soon. Added this one to a future project.

Keep us updated with progress and photos.

Thanks

pfbz

[double post-ignore. Forum server is doing some weird things!]

alpine003

double post

alpine003

Guys, just to clarify for some, this is only for '99-00 owners where OBC feature didn't come out of the box like '01+ models did.

If you have a '01+, you already have that functionality.

However, I still find it interesting that this was hidden on the '99-'00.

pfbz

My kind of mod! Though I already have the computer on my '04, so no direct need...

I don't know about creative, but I wanted some extra buttons for hidden garage door openers and didn't like the graphics or the cost of using repurposed Porsche OEM dash buttons.

I put some simple black pushbutton switches on the lower batwing between the heated seat switches. Easy to access & drill, and a replacement OEM batwing is only about $10 if I ever want to go back to stock... You could even use a small momentary double throw toggle instead of a pushbutton to mimic the operation of the stalk. The location is not quite as convenient as higher on the dash, but I think you might be surprised how little you change the mode once you have it set to the display you like most.

frisbee91

Yes, momentary switches are all you need to interact with the on-board-computer. You need 2 or 4 contacts, depending on which functions you want to access.
The 4 functions are up, down, set, and reset. Up and down are redundant, since you can just continue up until you circle to your choice. Set is only needed for the speed gong, which I wont use . So, I can get away with one two-contact momentary switch.

Now, who has done something creative with a button so that it looks like it would control the OBC?

alpine003

Does anyone know if the Seat Heater switches are momentary? I'm too lazy to take mine out and check.

Been meaning to wire up my garage door opener to a factory switch but once again too lazy and down on the priority list.

pfbz

I think you also use 'set' to set the default mode you want displayed.

pfbz

Pretty sure it is a two-way momentary. Push it on one side, it momentarily connects pins 1-4, the other pins 2-4, no press, both circuits open.

alpine003

If it is 2 way, even better as I can assign one of the sides to an x10 controller to control the driveway lights or one of the other lights in my backyard. Thanks.