[brucepick]

Linear Logic stood behind their product for me too.

I had random resets of the SG, where it would start reporting ridiculous mpg data. They sent a replacement cable, and also replaced the SG. If I recall, they replaced it twice.

I finally found the cause of the problem. 12V power from the OBDII connector to the SG was unstable, causing the SG to lose its "Mode" setting (ISO, CAN, etc). I discovered this when it failed immediately after flashing my headlights, and also after using the horn. Those apparently draw their power from the same bus that supplies the OBDII 12 volt pin - or some similar/related interference. Maybe the interference is on the ground side.

Another confirming observation is that the frequency of my SG failures increased significantly after I increased the display brightness setting. With it drawing a bit more power, it was more prone to power supply issues. But I only recognized that after the fact.

Anyway, I spent several hours wiring up relays to power the headlights and horn directly off the battery, not via the oem rat's maze of thin wiring. SG problem solved. NEVER a reset since then, and it's been a half year or so, driving about 400 mi/week.

I could probably have fixed it by running a good solid 12V line to the OBDII connector's 12V pin, and the same for providing a good solid ground. However, it's cramped in that area, and any error would be telegraphed right back to the computer - not a good idea. So I built the relay setup and I've never looked back.