[b3lha]

Originally Posted by SVXdc

Pin 4 on the Select Monitor harness (which Subaru also refers to on its wiring diagrams as the "Data Link Connector") is connected to pin 5 of the Cruise Control Module. Has anyone determined what that pin does? The wiring diagrams show only those two things interconnected.

I've started making the older-style Subaru radio harnesses with both illumination wires. A byproduct will be extra 9-pin harnesses, which I'm planning to offer to people who want to build a Select Monitor / DLC port interface. These harnesses will have only the 4 wires needed for the Select Monitor (Black, Red, Green, and Violet for Ground, +12V, TxD, and RxD, respectively). Price will be just a few bucks. If interested, please e-mail me (see my harness for sale post).

If we discover that the cruise control pin is useful for anything, I can throw in an extra wire so people can access it.

Also, the USDM SVX wiring diagrams (both '92 and '96) show DLC pin 8 connecting to pin c15 on the ECU. The DLC harness in my '96 has no wire there. Is that wire present in earlier years? If so, has anyone figured out what that pin does?

In the select monitor code there is an extra step involved when sending commands to the cruise control unit. I think it must be some sort of flow control using that wire. But LAN opened up his SSM and found the wire is not connected internally. It doesn't make much sense.

http://www.subaru-svx.net/forum/show...&postcount=127
http://www.subaru-svx.net/forum/show...&postcount=128

It would be nice to learn a little more about how the cruise unit works. I wonder if it is possible to simulate a drive by wire throttle by using a laptop to adjust the cruise speed up and down. That would open up all kinds of cool tricks. For example: using some sort of range finder to match speed to the car in front, or using GPS and setting the car to follow the prevailing speed limits.