Carrera Gauge Swap - 986 Forum - The Community for Porsche Boxster & Cayman Owners

KevinH1990 · 02-09-2015, 07:05 PM

On my 2000, I had to do the EPROM programming trick to get the voltmeter to work. That may be a difference between the "old" and "new" style clusters. The oil pressure gauge worked fine after I hooked up the 996 sending unit and inserted the wire in the back of the cluster.

The programming should also took care of the speedometer error and the top motion light. However, the top motion light on my 996 cluster worked before I programmed it. The VIN stored in the cluster indicated it was from a coupe, but it had the bulb already installed for the top motion light. So, the VIN decoder site may have had an error.

There was quite an extensive discussion on Renntech about this and most people indicated that the dealer couldn't help them.

Reebuck1 · 02-10-2015, 07:58 AM

Thanks Kevin ! My problem was I could not get my EPROM reader to read the chip in on 986 mother board. Chip showed # as ( sc 56M ). This was not listed in the EPROM inventory. I tried entering the 93c56B chip
number but it showed no data when I tried to read the 986 chip. So I could not see the data on the chip. I had to take the car to the dealer because of a window issue that turned out to be a bad theft control unit.
(Waiting for part to come in now.)
I figured while I was at the dealer I would have them turn on my new cruse control install and also turn on the two new switches on my 996 gauge swap.
They tried BUT failed.
Reason appears to be the result of my installing the 996 motor and having my
986 DME flashed as a 996 ROW. The guy who did my re-flash locked the DME so it would not revert back to the original 986 coding if I disconnected the battery.
SOOOOOOOO we are trying to work our way through this.
Any thoughts on how to get at the flash chip?? It would be easier if I could just do the mother board chip instead of having to go the DME path.

Trey T · 02-10-2015, 08:55 AM

Sounds fishy....

People only flash ROM, right? If so, ROM doesn't get erased or reverted back unless there's another device/software piggy-back onto it to give it a command... which sound really odd.

I don't much about Porsche ECU programming, but to me, I have never heard of such thing for other cars.

Quote:

Originally Posted by Reebuck1

... The guy who did my re-flash locked the DME so it would not revert back to the original 986 coding if I disconnected the battery.
SOOOOOOOO we are trying to work our way through this.
Any thoughts on how to get at the flash chip?? It would be easier if I could just do the mother board chip instead of having to go the DME path.

Reebuck1 · 02-10-2015, 12:39 PM

I am no expert. In my case I installed a 3.4 996 motor in my 98 Boxster (986).
My 986 (2.5) DME could was not programed run the 3.4 996 motor without a re-flash.
I had two choices:
1) a USA flash that would use the existing secondary air pump and related vacuum tubing. or
2) a ROW (rest of the World) flash that would allow me to remove the secondary
air pump, etc.
I chose the second.
When I was at the Porsche dealer trying to get them to turn on my reciently installed cruse control. They made the comment that the DME was locked.
I assumed that it was done by the individual who did my ROW flash in order to keep the DME from reverting back to the original 2.5 USA flash should the battery be disconnected.. That assumption could have been incorrect.
Can anyone comment???