Check engine light on, need to replace air pump relay. Where is the relay located?

 

How are you sure its the relay and not the pump itself?
But... the relay is in the PCM box.

 

Never heard of that relay failing, though of course it's quite possible.

Make sure by running 12v to the two motor poles, far more likely that it's dead.

The relay is in an ugly place, and now that I look at it, looks expensive.....

Remove ECU cover,
remove ECU,
remove ECU cooler duct (black plastic, flat)
the closest thing to the headlight is the relay, black.

S