Secondary Air Injection Pump failure

Yes with one caveat. To also be able to remove both air switching valves(ASV) you would need to replace each one with a Pressure Sensor Option (PSO). You can find them here: GenII Kit,PSO.
Basically, the ECM still needs SAIS pressure sensors to use as barometric sensors, it just so happens the GenII connects to them as well. So you either use the factory sensors in the ASVs or you replace them with PSO if one is damaged or you want to remove the valve. In most cases on the 5.7L engine you are just going to leave the good or bad valves in place because you would have to remove the intake to remove them.

In contrast, our V36/V54 units would need several kit addons to remove all of the components because the V36/V54 kits only prevent the system from running and the air injection control driver is looking at all the components. The GenII kits replace all that and don't care about the air pumps, air switching valve solenoids or air injection control drivers, just the pressure sensors, the factory air switching valve wiring and the ECM being in good condition.

 

Thank you. This is excellent information.

So if I get the genII kit, but do not get the PSO, what would happen if I was in the middle of no where and a ASV failed? Would my truck still be driveable? Or would it go into Limp Mode? I'm trying to weigh the cost/effort vs benefit.

What I'm looking for is to remove a system that is known to cause problems so I am not stranded in a remote area. But within reason.

 

It is rare for a factory air switching valve pressure sensor to fail without it having been exposed to exhaust gas first. So, if you were only getting a valve stuck closed code there is no more chance of the pressure sensor going bad at random than any other sensor on the vehicle. Basically if you get the kit installed and don't already have an indication a pressure sensor may already be damaged its not something to really worry about.
I can think of only two that have failed way after the fact and they were both already questionable because of exhaust exposure.

The cases we know you have a damaged pressure sensor that needs to be addressed and how they relate to limp mode. This is applicable to all of our kits.

1) You have a pressure sensor circuit code P2431, P2432, P243 for Bank 1 or P2436, P2437, P2438 for Bank 2. These are obvious and are 90% of the time the pressure sensor is the cause from extreme exhaust exposure. The other times are attributed to damaged wiring from rodents etc.. and in the extreme cases of driving the vehicle with a damaged pressure sensor for a very long time, a damaged computer.
If you have any of these codes you will be stuck in limp mode. They are hard circuit fault codes and can't be cleared.

2) You have a valve stuck open code that comes back when the engine is not running or it comes back on after you already have the kit and exhaust block off plates installed. No exhaust pulsations and still getting a valve stuck open code is the most common type of damage we see. This is also how we determine if you have a damages pressure sensor where there is not one of the circuit codes above and can confirm the vehicle has been driven that way for say a month or more. The procedure below will tell you if the sensor is damaged when you have been getting valve stuck open codes that come back on all the time or instantly after clearing. You must have a scan tool for this test since the CEL will always be on when the ignition is ON and the engine is off.
a) warm the engine up for a min or two
b) turn the engine off and switch the ignition back to the ON position without starting the engine
c) use the scan tool to clear the trouble codes and let it sit with the ignition ON and engine OFF for 10 min
d) after 10 min. re-scan for trouble codes.
If you get the valve stuck open code at that point you know that pressure sensor is damaged and you need a PSO (GenII) or PSRH (V36/V54) for the same bank as the code.
You still may be able to operate by clearing the code if the sensor is still in an intermittent stage of damage but most likely you will just get stuck in limp mode and not be able to get out of it.

3) You get everything installed and have been without codes for a few trip cycles and then get an evap/pressure sensor correlation code. The ever so slightly damaged pressure sensor is almost 100% going to be the same valve that you were getting a valve stuck open code from and it needs to be addressed. This test can't run if there are any other codes present so very rarely it has showed up after the fact.
This code does not put you into limp mode but you won't be able to clear it until both pressure sensors and the evap. pressure sensor read within 5-6kPa of each other. The only way to know for sure which of the three sensors is causing it is to compare all three sensor values on the freeze frame data. The odd man out is the problem sensor. I have seen 2-3 cases of it actually being the evap. pressure sensor as the customers had no previous secondary air problems.

My basic opinion is that the GenII would eliminate almost every cause of being caught off guard with limp mode. If there is a problem with a pressure sensor we can address it during or you will know it immediately after installation. I would not worry about a pressure sensor going bad after the fact unless it was already well exposed to exhaust for a while or I was in true wilderness. In the most extreme case I would carry a single PSO or PSRH in my parts locker but I wouldn't just install them. Most likely your factory pressure sensor would have a failure rate close enough to the sensor you replaced it with so just keep one as backup in the extreme case.

 

Awesome. Great information

My AIP system is working fine, no issues. Like I said, I'm looking to bullet proof my truck since I am frequently in very remote areas.

So it sounds like I should install genII and carry a PSO in my parts bag. How hard would it be to install a PSO in the field?

 

Any link or part number for this kit?

 

I just noticed that Hewitt Technologies has significantly reduced the price of their original bypass kits. A no brainer for me since I currently don’t have any issues, just doing as prevention.

Just ordered mine now!

 

The 5.7L cowl clearance varies a little bit from model to model but you can install a PSO in the feild with little to no tools. The trick on the 5.7L is just getting your hand down to the air switching valves and being able to squeeze the locking tab on the connector and pulling it off the valve.

Here are our GenII kits, SKU: GenII

Yes, The V36 and V54 kits are on a huge sale this month only before going back up.

 

OH WELL , Here goes the charge card again, just ordered the GEN II KIT , no problems with my 4.6 yet , just not taking any chances. Not sure what's gonna hurt more , prevention , or me later when I tell wife.

 

I think you can make a good argument for it as saving you a lot of money and headache since it can be upwards of $3000 to fix when it fails. You would also be able to take it off and possibly transfer to another Toyota. We could sell you a new harness for a different vehicle if it uses the same module.

 

What do you mean by that ?

 

Make 100% sure it isn't covered under warranty. I had the same problem with my 2012 Tacoma. I contacted Toyota directly thru their website on the problem and they called me the next morning. They had extended the warranty until I do believe this next February and then it will be based off of mileage. It was going to be expensive but ended up not costing me a dime. That was done earlier this year. They had a extended warranty campaign on it.

 

Yes. Best to get replaced under warranty first then bypass. That way if you sell or trade you can just take the bypass off and it's good as new.

 

Just ordered my bypass kit!! Are the exhaust plates mandatory?

 

The block off plates are an integral part of the solution and the whole kit should be installed at the same time to avoid your exhaust valves from causing problems in the future.
They are not always 100% required when first installing the kit. In the case of installing for prevention they can be omitted. However, if you are already getting valve stuck open codes the need to be installed. The block off plates are the only thing that prevents the air switching valves from leaking exhaust and causing limp mode. Basically, even if your valves are OK right now and are completely closed the valves have still been known to leak later on and cause problems. You can install the module only and see where that gets you but if you have any valve stuck open codes back on you have to install the block off plates. If you can get by without them and just the module make sure you put them in the glove box with the instruction so you know where they are if you need them later. The install really isn't hard so it is just best to get them installed regardless so you don't have to worry about it later.

Check out the 5.7L block off plates installation video and share your comments on it.
5.7L Block Off Plate Installation Video

 

Thanks for the quick reply! I have a valve stuck closed code but regardless I will put them in when I put the module in. Thanks for the help!!

 

@hewitttech

Im getting ready to order the GenII kit. Any coupon codes?? How fast can you ship it to me?? I want to install the block off plates this weekend as I am installing long tube headers.

My plan is to completely remove the AIP pumps and plumbing. I will leave the ASV in place as I have no indication that they are bad.

If I understand this correctly, I can carry a PSO kit in my parts bag and if I am on the trail and an ASV goes bad, I can simply plug in the PSO. is that correct? Or is the process more involved??

 

I DAP tuned my '07 5.7L @ 281,000, one of the many benefits of the tune is that it turns off the secondary air injection pumps... I never have to worry about this failure.

 

I don't want them turned off, I want them physically removed from my truck

 

Good luck with that.

 

Why would I need luck? Is there a risk involved?

 

I can't comment on the risk factor because I have not read where anyone has removed the system.

 

Ok, I was just asking because you said "good luck" like as if I was doing something wrong LOL

Seems simple enough to me. Add the bypass kit, remove system. I want the extra clearance in my wheel wells as a secondary benefit

 

@Rex Kramer, can that be done on a 08 4.7? I have already had my AIP'S replaced. My truck did go in limp mode a while back, I unplugged the negative terminal and all is well. Thanks

 

I like you live in CA, removal of the AIP system may cause a smog check visual fail????
Just something to consider!

 

I purchased hewitt kit , and I believe they told me once installed pumps can be completely removed . I'm going to verify with them 1rst .Once I get started with bypass.

 

Not that I am aware of... contact DAP tune to see if they have anything for the '08 4.7
Sadly, they don't have anything for my '02 4.7

 

Yes. If your county requires smog check, then it'll fail visual. Not all counties require smog check

 

you gonna clear smog check with the long tubes ?

 

Thanks, I'll look into it

 

I'm not worried about it