Hey honda-technicians,
I currently have an issue with my civic. Emissions time has come around and plugging in my Obd2 P2t, I got the p0505 IACV Malfunction code

Car: Obd2 99 Civic Si
Motor: 95 Obd1 Gsr, Full swap using cars original harness
Ecu: Obd2 P2t


The car currently has a 2 wire IACV.

The plug B of my car currently looks like what the picture attached is instructing (with a Blk/Blue Wire in b23 and NO wires connected to b6 & b15)... (Since there are two blk/blue wires, Idk which of the two is in B23, whether its the IACV or IACV Positive)





According to the p2t layout, b23 is where the IACV blk/blue wire should go, b6 is for the Positive IACV side Blk/Blue, and b15 is where the Negative side Orange wire should go

Questions (Since im trying to get rid of the CEL):

1) Do I need the Obd2 IACV or just the three wire pigtail plug? Or Both?

2) Correct me if Im wrong but isnt the picture that i posted showing the "fix" to making the obd1 IACV compatible with the obd2 to obd1 harness to be able to run an obd1 ecu?

3) Since my car right now has NO wires in b6 and b15 (Positive and Negative IACV) (according to the p2t pinout), could that make the CEL pop up? does that have an effect at all? Should these two wires be connected?

4) What should my wiring look like? How it looks in the picture before moving B6 to B23 with orange wire in B15?

5) I have tried to look for the two missing wires b6 & b15 but I dont see any cut or Orange & Blk/Blue wires. What do I do without them?




THANK YOU IN ADVANCE ! Sorry if everything seems confusing i just want to get passed emissions in NY. I am very inexperienced with these electrical issues so I came to the forums hoping a real Honda head can help. Ask questions if needed, I can take pics as well if needed.

I appreciate any help! THANKS again.

-Serg

 

Its not about compatibility, its to show you how to convert your automatic iacv plug from a 3pin to a 2 pin.

 

P0505 would NOT be thrown by an electrical problem in the IACV circuit. In addition, your OBD1 swap is fully compatible with a 2-wire IACV.

Clean your IACV.

 

Thanks for clearing up the electrical mix up.
I have already cleaned the IACV, could I try anything else? Before spending 200+ on a new one...

 

No idle issues whatsoever? Did you reset the ECU to see if the code returns?

 

We checked for leaks, none; Cleaned out everything. My dad reset the code with his scan tool and we ran it about 150 miles and it didn't pop up so we took it to get inspected. They showed us their scan tool and the code IACV Malfunction came up. They said if I were to run it more, the code would pop up.

I'm just confused on to what is causing it