What does the integrated control unit in a 1990 acura integra do?

there really isnt. a 90-93 integra has the b18a1 engine and the 94-95 integras have the b18b1 engine. the only difference is some small wiring differences and sensors that were added to the 94-95...

Under the dash. Mounted to the firewall. There's a red flashing light on the bottom side of it.

Try behind the grill but in front of the rad

OBD 0

FFirst remove interior rear panel to gain access to the retaining bolts then unbolt the taillight after all retaining bolts are removed wiggle the tail light loose and that's it