Secondary air injection switching valve.......?

What year is your truck and mileage? The link above in billybob's post is for the company that sells the bypass kit bit the system has to be operating correctly to install it from my understanding.

 

My truck is a 2012 with 36k The link only goes to 2007.

 

You are correct on the link, I have an email out to the company to make sure the wired Version will work with our trucks. If your out of warranty I would just fix yourself as you can get the part online for $425 and install in 30-40 min. Also make sure to call Toyota and express your frustration with this part failure. The more of us that so the better and Toyota might actually do something for the Toyota crowd.

 

My 2012 runs at every cold start up as far as I am concerned, though I am not always listening for it.

I didn't really catch it in this thread, but do you have the link to the mod or the post number to Billybob's bypass? I am most likely going to do this. I am at 60K on my 2012 no AIP problems, but I am not going to risk it.

 

There isn't a kit for the 2012 yet. I'm trying to contact the guys who make it but they haven't got back to me.


And I know I can change the parts very easily I just don't want to keep forking out 500 every few years to fix an issue that shouldn't exist. Beyond frustrated

Does anyone have the part numbers of both valves for the 2012 4.0l

 

I agree. $500 for a part is nothing to sneeze at. It's not like we all just piss out money either.

 

So have you had the issue previously? The part# 25710-31022 is what I just purchased this last Thursday for $470 and was able to find it locally. There list on the part was $643.72, if the bypass wont work for the 2012 trucks then I will be trading my truck off as I refuse to fork over more money for this issue or be stranded somewhere because of it. Weird that the site with the bypass even list Tacomas pre 2012 as they didn't even have this system.

 

Interesting as most say there pumps run at every cold start, today is 27* here and my pump has not run 1 single time on cold start.

 

Twalt forgot to mention that the part# I gave you is the most recent one, I'm still trying to find out if they have improved the part any or if it just changed for inventory reasons. Past part#'s were 31020 and 31021.

 

No, light just came on a few weeks ago. I have been clearing it as it came on but now its hard set for both valves. I will pull them apart and see but I have a feeling i know when im going to find lol.
Im not buying the parts just yet, doing more research on an alternative.

Going to call Toyota again tomorrow.

 

When is the last time you went to the dealer and they did any sort of ref lash to your ECU?

I am also supercharged so they may have altered the AIP parameters to allow it work at every cold start up as well.

The design and functionality is as it should be in theory because upon cold start up you are in an open loop situation, and since the engine is cold, more fuel is required to allow it to be properly combustible. More so than the ECU allows, so that's why they allow the temporary Open Loop parameter. The AIP system is in place to allow for further emissions clean up of the engine while it is cold, so only while it is cold it should always run until closed loop is allowed to properly engage and allow fuel control over the system. The pump helps clean up approximately 50% of the emissions until ECU fuel control can take place.

Again, the theory and functionality of the system is correct and as it should be. (Do I like it? Hell no.) The execution and physical design of it is clearly where Toyota falls on their face.

 

Good luck, I have a case manager with Toyota corporate on the issue as we speak. When I pulled mine apart the rear most valve was the worst as you can see in my pictures further back. I tried to clean up and install to see if it would buy me time but no luck, the truck would instantly set the codes and place it in limp mode. After getting dicked around from the dealer and missing two days of work not being able to drive my truck I gave in and bought the valve set and installed. Good luck and keep us updated.

 

My truck was in for the pinging reflash this past summer, I don't know if that changed any of the AIP parameters or not. I to understood its supposed ti run during all cold starts but mine does not when its below 40* it seems like.

 

It almost sounds like the diverter valves or the pump itself could potentially be sticking and/ or physically frozen while you are at or below those temps. The housing for that setup is built out of aluminum I believe, and aluminum is excellent at temperature transfer, so it gets really hot just as quickly as it gets really cold. If it is not working below those temps, I would be more inclined to assume that you may be having more of a hardware failure before a software failure (or lack of proper software programming).

Also, I don't believe that the pinging reflash from the dealer at any point touches the AIP program. So they may have never touched it at all. I know they have reflashed my systems several times due to various reasons. The final being the blower. So you probably still have original parameters built in. I could be wrong though.

 

Pulled my rear one off just now, soaked with water and the rubber is deteriorating. I pulled off the hose that goes to the air pump and its full of water, lots of water. So im guessing water is being sucked in from the air pump and pumping it into the valves. The amount can't be condensation can it? I think im going to mount it into my air plenum so it draws air from that.

I might try something here.
http://www.dormanproducts.com/p-81086-911-643.aspx?origin=keyword

The dorman part i linked is for the tundra, but as far as I can tell the valves them selves are very close to being the same. I may buy one from my shop, take the valves off and bolt em to my truck, if it works then great. Its 200$
If not, ill say its wrong and send it back at no charge ;P

 

I would agree with you if I still had my original valves but the new set is just a couple days old and I cannot see it already failing or sticking. Still a mystery why the AIP doesn't operate for me though on very cold starts.

 

I believe its condensation, the pump is high up on the inner fender, where would it suck water from? Mine had water in them as well, especially the rear valve. Are your check valves stuck open? (they are the orange flap)

That Dorman product looks promising, the only thing I can see you might have an issue with would be getting the harness to the rear most valve as its connector is pointing in the wrong direction.

 

They are yes, theres a ton of carbon built up between the plates. On top of that the valve itself isnt sealed, i can blow and suck through the port at all times.

 

I think the rubber helps the valve to seal so if its gone like mine was then your not going to be able to just clean it up and reinstall. From my research that orange check valve gets the carbon build up like we both have seen and begins to stay open allowing the hot exhaust to then reach the rubber and destroy it. As for the Condensation there is no way for it to evacuate it. 13-up trucks and now newer tundra's cycle the pump post shut down for a moment to help combat this issue, us with 2012's are not so lucky.

 

Twalt reference this thread, looks like the OP successfully installed the bypass on our trucks.

https://www.tacomaworld.com/threads...ion-bypass-kit-2012-4-0.394629/#post-10901542