quick obd1 p72 question
 

I have heard that there COULD be a minor difference between obd1 p72s, and obd2 p72s. In obd1 i believe the ecu sends a 12v signal to the IABs, and in some of the obd2, the ecu sends a ground.

Is there any truth to that? Have any of you ever run into a situation where an obd1 p72 does not properly run the iabs on an obd2 motor?

sorry if thats a stupid question, but inquiring minds want to know

edit: my car is a 2000 gsr, obd2b for you kids not in the know. i am acquiring an obd1 p72... and i just want to clear the air about whether or not it will run iab's correctly

That would be against all honda principles.

My prelude is obd2 and with the stock ecu the IABs work fine (of course). When I had the hondata setup in with an obd1 p72 they also worked fine.

The only way that yours would be different is if honda decided to change that system when they changed from obd2a to obd2b. Which is very unlikely.

IAB control on P72

OBD1 - 12V active
OBD2a - 12V active
OBD2b - ground active

to go from OBD2a to OBD1 simply switch the wire on the other side of the IAB solinoid to ground. Of if you want plug and play toss a relay into your conversion harness to switch the signal.