1997 DME for 3.4 swap

[Smallblock454]

For a 1999 engine you'll need a 7.0 DME.

A 1997 986 will have a 5.1 DME - not compatible, because it hasn't the correct in- and outputs. Also the engine wiring harness is different.

If you get an 7.0 DME from a 986 the mapping needs to be flashed for a 996 3.4 engine. This can't be done by OBD. This always needs to be done on the bench.

Check what alarm control module you have. If you have a M531, you'll need to update to an M535. If you have a M535 it can be reprogrammed to work with the newer DME.

If you need to update from M531 to M535 the wiring harness has to be updated too.

[78F350]

I'd buy a full set like this. After the 3.4 is installed and verified good, I'd sell the 1997 set that was originally in the car to recoup my cost (because I'm cheap like that).




Autobahn Parts - Electrical, Porsche 911 996 OEM 1999 Carrera Alarm Control Module + ECU + Tumbler w/ Key, 996.618.601.04, 996.347.017.07, 996.618.260.05

or

https://www.ebay.com/itm/334397963288? *Their eBay feedback is a bit low for my comfort, but reading the details they seem legit.

[78F350]

Originally Posted by Smallblock454

... If you need to update from M531 to M535 the wiring harness has to be updated too.

It's been a couple years since I looked at it, but I think the only difference in the wiring is an additional shielded wire for the antennae connection. If needed, I have a harness in a 2001 parts car that should have it.