Air Injection... AGAIN

[Awz]

Okay, so I've been fighting this nearly since I've owned it. Originally I had P2440, so I replaced the pump and the valve. Light came back, I bought the bypass kit, with the block off plates. Didn't work. I splurged and bought some Doug Thorley headers to fix the exhaust leak. That didn't work either.
About a week before I did the headers I saw P2433. Didn't throw it into limp mode, wasn't too worried, headers were in the mail. This morning I woke up to P2445, p2433 (I didn't clear the codes). Then p2440 popped on the way to work. So I have a valve that's stuck both open and closed.
I've about had it. It's been to four different shops, two of them Toyota dealers and no one can tell me what's going on. Everyone want's to dig in under the intake again to make sure everything is correct.
ANY help would be appreciated. I think it's the ECM, but Toyota won't replace it unless THEY diagnose it, and they can't figure it out.

 

[LOSTR4]

Have you tried the 'ol ECU reset? Disconnect the battery for an hour and re-connect...see if that helps at all...a perfect lunchtime task!

 

[Awz]

I drive with a code reader constantly hooked up. But I'll try disconnecting the battery at lunch.

 

[Awz]

No change. If anything it's worse now.

 

[duffdog]

I was playing with Techstream last night and saw that you can individually open and close all the valves and start and stop the AIS system with the Active Test button. If you could find someone with techstream and a VIM in their possession Im sure you could figure it out.

 

[Awz]

duffdog,
I've already tested that. Valves and pump command on and off.

Light rarely comes on if I'm just idling or at constant freeway speeds. From a stop it will sometimes come on as soon as a touch the throttle. At freeway usually not until I try to pass someone. Going into limp when you're trying to pass is fun. This is not always the case. I cleared the code twice on the way to breakfast this morning. Then didn't see it again on the way to work. Combined freeway and city roads.

It doesn't seem to want to make up its mind. Last week I only saw it once on Friday and I was running several errands. 02 sensor maybe? The muffler shop did a smoke/leak test on my exhaust and didn't see anything.

 

[duffdog]

duffdog,
I've already tested that. Valves and pump command on and off.

Light rarely comes on if I'm just idling or at constant freeway speeds. From a stop it will sometimes come on as soon as a touch the throttle. At freeway usually not until I try to pass someone. Going into limp when you're trying to pass is fun. This is not always the case. I cleared the code twice on the way to breakfast this morning. Then didn't see it again on the way to work. Combined freeway and city roads.

It doesn't seem to want to make up its mind. Last week I only saw it once on Friday and I was running several errands. 02 sensor maybe? The muffler shop did a smoke/leak test on my exhaust and didn't see anything.

"tested that"? What do you mean by that? What did your freeze frame data show when you were driving? did you get a high or low signal from the pressure sensor when accelerating? Truly diagnosing the problem means you will have to drive around with the VIM connected to the car and a laptop in the passenger seat and monitor all the AIS values in real time and compare them with the values stated in the factory service manual.
Since p2433 is a pressure sensor problem and you have not let us know if the pressure sensor is working or not from Techstream, I suggest you start there.

 

[Awz]

The sensor has been replaced with a factory Toyota part. The shop that replaced it couldn't see any problems with the new sensor while monitoring it on the scan tool.

 

[loarmistead]

I'm not following. If the bypass and blocking plates are correctly installed, the computer shouldn't even be monitoring the AIP system, and therefore shouldn't be throwing codes related to it.

Sent from my SM-G935V using Tapatalk

 

[catfishbirddog]

The sensor has been replaced with a factory Toyota part. The shop that replaced it couldn't see any problems with the new sensor while monitoring it on the scan tool.

Maybe check your bypass wiring? If someone replaced a sensor AFTER the bypass was installed, they may have undone your bypass wiring or something. As previous post says, bypass should prevent this error electronically. Are you trying to fix (sensor, valves etc) or bypass? No need to do both.

If bypass wiring is correct & plates installed, I have no idea. Probably a worthless post but this pic is my fuse connection to bypass from the drivers die - purple wire from bypass to passenger side of purple fuse. That's my scientific technical description

Edit - PS: random thought, ever clean your mass air flow sensor in your intake? Real easy - all you need is a screwdriver and a $4 can of electrical cleaner spray.

 

[blackoutt]

I'm with everyone else. If your bypass is hooked up properly (and not faulty) it shouldn't throw a fault because it will never be running the logic to check for conditions out of spec. Maybe try another bypass module, ensure that relay is working properly.

 

[BoostinZX]

Not sure if this helps, but I had purchased a cheaper bypass which worked for a while and then seemed to stop working after a bit... I purchased a more expensive one from hewitt tech and haven't had the codes since... I am however dealing with an ongoing p0172 & p0175 issue, but i don't think the 2 are related... at least i hope not Good luck with your issue man... I know its frustrating... I've been dealing with this one off/on for 3 years now...

 

[Awz]

I used the hewitt tech. Even they didn't know why it would keep throwing codes. The plates were installed correctly, I did it myself, pretty straight forward. It's always been the same code P2440. The first code that popped after I bought it. The first code to pop after the pump and valve were replaced, the first code after the bypass, the first code after the exhaust leak was fixed. I'll have to try cleaning the MAF tomorrow. It's strange. Driving around last night, cleared the code three times until I hit the highway. Drove around a few places and didn't see the code again for almost 3 hours, around town and highway driving. Leaving work today I cleared the code probably 10 times on the way to the store. Then it stayed off until I got home.

 

[wabibem]

Did you ever figure this problem out?

 

[briholt]

I'm replying here because I don't have the permissions to start a new thread.

And I'm interested in whether it's time to do the VSV bypass.

I've got a 2008 V8 4runner and Have the CEL with VSV flashing. my torque app is saying I've got a p2433. I've reset the codes, it comes back. I've disconnected the battery, same code returns. Symptoms include limp mode. I can get up to speed on the highway, but only if I drive like a semi...nice and slow...Sneak up on highway speed. If I gun it, I just slowly increase speed.


Page EC-10 of the factory service manaul is attached

Checking rear VSV

1. INSPECT PRESSURE SENSOR
(a) Turn the ignition switch to the ON position.
(b) Measure the voltage between terminals E4-32 (AIP) and E4-28 (E2) of the ECM connector.
Voltage:
1.0 to 2.2 V

Step one I do not get enough voltages across the connecting wire. E4-32 to e4-28.

2. INSPECT VSV FOR AIR INJECTION SYSTEM
(a) Disconnect the connector from the VSV (Procedure "A").
(b) Disconnect the 2 vacuum hoses from the VSV (Procedure "B").
(c) Using an ohmmeter, measure the resistance between the terminals (Procedure "C").
Resistance
If the resistance is not as specified, replace the
VSV.
Tester Connection Specified Condition
1 - 2 33 to 39 Ω at 20°C (68°F)
1 - Body ground 10 MΩ or higher
2 - Body ground 10 MΩ or higher

When I check resistance and step two, I do get the correct resistance between the terminals inside the VSV on both, but if I check body to ground I do not get any resistance. It's open. That tells me that a ground wire is disconnected cut or chewed?

step 2 continued

Check that air does not flow from the port as shown
in the illustration (Procedure "D").
If the result is not as specified, replace the VSV.

The second check of the VSV is blowing air into the bottom tube and I am able to do that. Air will go through and come out the top. That is not to specs.

I cannot blow the other way, from top tube to the bottom, unless I supply 12 volts.. Supplying 12 V allows me to blow the top tube and air comes out the bottom tube.

(e) Apply positive battery between the terminals, and check that air flows from the port (Procedure "E").
If the result is not as specified, replace the VSV.

When I apply a 12 volt charge to the two terminals. I can hear a loud click inside and air moves freely, of course


Checking front VSV
Same behaviors. as above. Which makes me think both VSV didn't fail exactly the same way, it's a ground wire that is cut?


If the VSV's are fine and it's wiring, then I believe to fix it one must remove the intake manifold.

Or...one could do a bypass.

Am I missing anything? I think My results from step 1 (not high enough voltages) and that the VSV isn't closed at rest is telling me contradictory things...I'm assuming that limp mode means the VSV's are closed...but maybe I'm wrong.

Thanks for the look.