Honda Acura IACV Testing Basic (With Only 12V Battery) [Idle Air Control Valve]
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- Опубліковано 4 сер 2024
- Here we do some testing of a IACV off of a 2001 J32A2 Acura engine although most of the Honda / Acura engines of this age use a similar if not identical IACV. This is what it should do when exposed to very short pulses of 12V power.
Full IACV Testing. With PWM showing full sweep of the IACV: • J32 Miata IACV Idle Ai... - Наука та технологія
My IACV is a plunger style. there's a visible shaft inside with its return spring clearly visible. I plan on doing your electrical test but wonder in the meantime if the plunger is frozen in the IACV because I cannot move the shaft at all with a screwdriver in any direction. Seems locked in a closed position. Great video, tx! Also, I've cleaned the IACV 3 times with carb cleaner. Idle description:
once the truck is fully warmed up in gear, the rpm's at are at 400 and in neutral the rpm's rise to 700-800.
Got a P0505 and put a brand new one on, still surged idle. Pulled it back off and gave it power and ground and the new part was defective from the box.
Is that all its supposed to move? Or is it supposed to open up all the way??
I don’t think you explained the current limiter. Used a 12V power supply w/ 2A current. Caused spark. Will exceeding current damage the IAC to where it’s untestable? what amperage / power range is acceptable?
I was testing with a battery and had the same problem with sparks hoping for a reply because I need to fix this asap
Is the IAC controlled only when in park/neutral or is it also controlled when it is in gear?
Reason I ask is because I have a rough idle that surges when in park/neutral. Once I put it in gear it smoothes right out. I am stumped.
IACV is controlling idle speed with ignition timing all the time the engine is running.
Thx for this tip. So, I have an 04 element, and have a P0507 code. Took out the IAC valve, did the test as you performed. The door was stuck in one position. So I went ahead, and disassembled it. Spindle was gummed up, not much but I guess enough to trigger the DTC, and unstable idle. Cleaned it, and lubed with 3 in 1 oil, and spindle is free as a bird. TESTED it again with 12v direct from a month old batty., and still the same result. Door not moving. Now, if I hook it up with the car's IAC valve connector, and key on, I could feel a vibration through my short flat tip screwdriver, but door is not moving again, prolly at default position. DOES this indicate an electronic failure of the assembly? IAC is aftermkt, and about 4 yrs old, Standard Motor parts brand. Thx for any inputs shared.
Vibration typically means it's working as long as it's consistent for further debugging I would back scope the IAC under usage and see the PWM to ensure the signal the ECU is generating and rule out one side or the other...
Does anyone know the resistance values between 1-2 leads, 2-3 lead and 1-3 leads f the iacv? If there any tech manual/diagram out there?
1-2 15- 20ohms
2-4 the same
Hi this is a test I was looking for, I'm dealing with a 2003 odyssey. It stalls at cold only when in gear "D" and the brake pedal pressed but if you let go the brake pedal and let the van runs without accelerate it doesn't stalls. The van runs and idles smothly once the engine reaches operating temp but I took off the IAC and it doesnt turn freely by hand.
Did you replaced your iacv already?
So is the IACV constant 12v? And the ECU sends signal from ground?
In a way the idle air control valve is a small motor that when nothing interacts with it resets to a known position when current flows through a coil it will pull the idle air control valve to a reasonably known position.
To change the amount of current flowing through that coil The ECU Will turn on and off a switch really fast connecting the other half of the circuit to ground.
The reason why the ECU switches on the negative side instead of the positive side comes down to some oddities with transistors where it's more efficient to switch a negative on and off than it is to switch a positive on and off. just like if you installed a switch on the positive side or the negative side of a light it would work all the same The ECU is doing the same thing.
So in short yes the idle air control valve is supplied with ground positive 12 volts and a PWM connection to the ECU which eventually will connect to ground through a PWM transistor.
in the video linked in the description and in the corner around the 30 second mark we go into a little bit more detail and use an microcontroller to create that PWM signal through a transistor.
@@concentricmachining4636 both top and bottom connector should react when connected to ground? Mine only reacts on one side. I assume mine is bad. Thanks for sharing this great info.
@@BLAZEPSI I'm currently troubleshooting a rough idle/stall. My IACV only reacts on one side as well.
@@concentricmachining4636 can you offer any advice towards Blaze Psi's comment? I'm experiencing the same thing as they are. My battery voltage is 11.6V instead of 12V, but that voltage is enough to activate one direction of the movement. Is it possible that the PWM side is more particular about the voltage being supplied?
@@concentricmachining4636 how to tell if my ecu is having trouble too? Besides the iacv? I replaced the iacv but still check engine is lighting,
This pinout explanation doesn't make sense. Why are both pins 1 and 3 control pins? And you can just attach a 12V signal to the device without completing the circuit with a ground?
When i looked at Acura service manual, it states that pin 2 is 12V and pin 1 (on connector to iac valve) is ground. The "default" state is the valve is in "closed" position -- which still allows some minimal air flow in this position. In default position, pin 3 is not activated by ecm and is 12v, When ecm activates pin 3, it pulls that pin to ground, opening the valve to its widest (and only) 'opened' position. The duty cycle of pin 3 determines air flow.
The IACV of my 2002 Honda CRV seems to follow your logic. I connected P1 to ground and P2 to 11V. P3 then reads 9.8V (1.2V lower). When I then tap P3 to ground the valve moves a little for a moment.
I'm about to build the suggested little Arduino tester to see the full range of movement of the valve.
@@cobbles62 if you have scan tool with bidirectional control, you should be able to adjust the iac valve through the scan tool. I'm going to do that this weekend.
@@yusuihang I would love to have one but the cheapest one I could find is $300+
Besides, if the valve does not work using the scan tool it could also be a wiring or an ecu issue.