Im experiencing an erratic ground when I have the FIC connected and turn the truck off. It doesnt come on immediately, usually about 10-30min after turning off the truck and it causes the air bag light in the dash to come on (SRS warning light is powered off the 7.5A ECU-B fuse). Its also very inconsistent, sometimes not showing up for days. It usually takes about 5-10 hours to drain the battery. If I disconnect the ignition power source from the FIC and then reconnect it, the ground goes away and never returns until I start and subsequently shut off my truck.
Ive swapped out the unit with a good one and experienced the same issue. Ive double and triple checked all the wiring (wire diagram attached in zip folder). Two power ground leads from the FIC are connected IAW instructions, one connected to E01 and one connected to E02. Signal ground connected to E1 (shielded ground for sensors). 12V power wire connected to IGSW (ignition 12v source).
AEM FIC forums are down and AEM FIC phone support sucks (they keep telling me Im wired to the "constant 12V" vice "ignition 12V" source).
Here is something Ive found in the Scion forums where the FIC keeps some sensors engaged when the ignition is shut off. I dont know how this will apply to me but I doubt this is the issue as Im pretty much the only 1st gen Tacoma experiencing it: