1998 CRV annoying CEL Light (P1508)

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Junior Member
To start I am a pretty seasons mechanic when it come to Honda, but this one is kicking my ass.

The Car is a 1998 Honda CRV EX AWD, I have had a check engine light with the cel code P1508 (IAC Valve Circuit Failure). I started with the basics and replaced the valve with a used one. I cleaned all ports in the throttle body, and manifold that lead to the IACV. That did not fix the problem, so I bit the bullet and replaced it with a new one. This did not solve the problem either. I replaced the IAT sensor after reading a couple threads that stated that sensor relates the that CEL code. This did not fix the problem either. With the new valve installed I turned the car on, and disconnected the harness going to the valve. The Idle did not change at all which leads me to believe that there may be a wiring issue. I can't seem to find a proper pinout, and wiring diagram for the 98 CRV AWD model (obd2-B?). Any help would be appreciated, this has been driving me nuts for a couple months now. The car runs great, and has no idle issues warm or cold. Thanks in advance for any info.

EDIT:the engine is a JDM B20, and the only mod is the crank angle sensor bypass. I don't think this should effect the IACV, but may be relevant.
I have a Helms for a B18C and B18B....not sure if its the same though. But I will take a look at the continuity tests.
OBD1 Helms for b series:
Key in "on" position and unplug it and check the voltage between yel/blk and ground. No volts....thats the wire
If it does have volts......turn key off and reconnect plug to IACV. Herlms says to connect a test harness to harness A at the ECU and monetarily connect A9 terminal to A23 terminal several times and listen for the IACV to 'click'....then they say if it does click.....try another ECU but if it doesn't click then its the blk/blu wire

Sorry this is all I got....no real OBD2B knowledge :shrug2:

I would try to hit up a local Honda place and see if you can spark a conversation with a technician and pick his brain to find out how to check the OBD2B system.