IACV Troubleshooting...voltage and continuity ???
 

UPDATE: Fixed it. Ran a new wire to the ecu and everything is good to go. tested the iacv and it was getting power fine. also it would click and open when grounded. didnt really feel like tracking down the bad wire in the harness so i just ran a fresh one.

Hey guys, need some help troubleshooting a code 14. 92 civic vx with 2 wire IACV (no conversion or anything) ecu is a p06 with hondata s300. idle is extremely low at all times. ive cleaned an replaced the iacv twice so im turning to the wiring.

from searching ive found that the iacv should get 12volts to one side and the other goes to pin a9 on the ecu. so doesnt this mean i should get continuity between a9 and the iacv plug? i cant get a reading on my ohm meter. i double checked my del sol and i cant get continuity there either. am i doing something wrong?

i was trying to follow these directions:

"You can also test the 2-wire IAC valve winding with an ohmmeter. Make sure there is no continuity between the winding and the case. Check for approximately 11.5 ohms on the winding itself."

also i found this diagram:

23.5 Two Wire IAC Valve

The 2-wire IAC valve is supplied battery voltage on one side of its winding and the ECM supplies an electronically simulated ground on the other side, as shown in Illustration 23-1.
http://thelic.org/users/tomo/IACV/Il...ion%2023-1.png

if i just wire the iacv myself, i can just run one wire to a9 and and give the other battery voltage with the key on???

sorry for all the questions, i'd really like to get this straightened out ASAP. TIA

Re: IACV Troubleshooting...voltage and continuity ???
 

The IACV gets it's power, [yellow/black (12V+)] from the output of the injector relay in the PGM-FI Main Relay in most Honda/Acura but on others the power comes directly from a fuse, [hot in run and start].
As long as you get power from a source that is hot in both run and start your good to go.

Yes the ground is supplied by the ECU/ECM, you can use a meter to test for power and ground at the IACV, DO NOT use a 12V test light. 94

Re: IACV Troubleshooting...voltage and continuity ???
 

so is it correct to assume that i should get continuity between a9 and the other iacv plug pin?

Re: IACV Troubleshooting...voltage and continuity ???
 

It is a coil, so yes you should get continuity, what the impedance is I do not know.

Have you checked to see if you have power at the IACV when ign. is on?94

Re: IACV Troubleshooting...voltage and continuity ???
 

yes i am geting 12 volts at the iacv with the key on.

Re: IACV Troubleshooting...voltage and continuity ???
 

should there be a particular voltage between the two pins on the iacv?

Re: IACV Troubleshooting...voltage and continuity ???
 

If ECU is supplying a ground then the voltage you read when metering the two pins would be 12.5V-13.5V. [batt. voltage] as you have voltage on one side and a ground on the other.
Have you metered the IACV itself for continuity, [impedance of coil]?94

Re: IACV Troubleshooting...voltage and continuity ???
 

no i have not. do you mean unplug it and just test the actual valve? what kind of readings should i be getting there?

unfortuantely the car is stored in my mom's garage so all my testing will have to wait until the weekend. im compiling a list of things to check when i go back saturday.

Re: IACV Troubleshooting...voltage and continuity ???
 

Yes, unplug and test the valve itself, sorry, I so not know what the impedance is supposed to be, but you are mainly looking for an "open" circuit. 94

Re: IACV Troubleshooting...voltage and continuity ???
 

In hondata s300 you can disable the IACV. I have mine disabled.. My car idles fine. If you dont get the wiring figured out.. Give it a shot and disable. it.

Re: IACV Troubleshooting...voltage and continuity ???
 

thanks guys, ill report back this weekend

Re: IACV Troubleshooting...voltage and continuity ???
 

bump cause my car is running again. thanks guys

Re: IACV Troubleshooting...voltage and continuity ???
 

My girl friends 1997 Honda Civic EX has me baffled. The symptoms cause the engine to cut out and surge once the engine is warmed up.
I get a code PO335. Crank Sensor circuit A.
All wiring was probed. A new Sensor replaced.
Well, I learned of a IACV (Idle Air Control Valve)
​​​​​​The 2 wires were probed. On one wire, 12V ignition on. With engine running 14Vs.
Getting continuity on the other wire and 10v with the key on. I am not sure if there should be voltage on each wire? I read on this forum that I should get continuity on one of 2 wires..
I unplugged the IACV wires.
The engine warmed up, I took it on a test drive.
The engine ran good with out the rev limiter symptoms.
I am not sure if unplugging the IACV can cause a hot water line to burst. But I seen steam coming from under the hood. The temp gauge was still in normal operating range. I stopped and noticed a water hose was leaking coolant.
The IACV needs to come off and inspected.
How do you bypass the IACV until a new unit can be installed?
Any in debt information would be great.