Secondary Air Injection Pump Failure on V8's! Important!

[NeutronJon]

Alright, so this is something that I've been fighting. I originally wanted to go the "correct" way and had the parts replaced. P2440 came back, limp mode. I bought the hewitt-tech bypass. Still getting the code. Bank1 valve open. The only thing I can think is that the sensor is bad. The block off plates are in place so they can't be getting a pressure spike. This is what Hewitt suggested but I wanted to get some other opinions, or see if anyone else has encountered this. I've spent $2000 so far on this POS and am tired of clearing the code all the time. The weird thing, at least to me, is that is only comes on after several short trips. 16 degrees on the way to work and no problem. Stop at the gas station, then the store, stop to get something to eat, I need to clear it a couple of times. (I have a basic scanner, no battery disconnect). Any other ideas? Are the sensors part of the valve assembly?

Thanks

Check out this page for instruction on checking proper operation of the sensor.

https://techinfo.toyota.com/t3Porta...html?sisuffix=ff&locale=en&siid=1482258436922

The page also links to a second page that describes how the diagnostic portion of the system works and what the specific triggers are for the related DTCs.

https://techinfo.toyota.com/t3Porta...cale=en&siid=1482258697855#RM0000012FY002X_07

 

[07V8]

The resistor has nothing to do with the valves. This is if you get a code for a bad air pump with the bypass kit installed. I'm not sure that the ECM checks the resistance of the motor before attempting to use it, but if so, I think this would work.

This is a theoretical solution for people who are not as good with print reading, are still getting pump codes with the bypass, and really don't have anything else to lose before shelling out the money on a new pump.

@slyfox any thoughts?

 

[Stuffman]

The resistor has nothing to do with the valves. This is if you get a code for a bad air pump with the bypass kit installed. I'm not sure that the ECM checks the resistance of the motor before attempting to use it, but if so, I think this would work.

This is a theoretical solution for people who are not as good with print reading, are still getting pump codes with the bypass, and really don't have anything else to lose before shelling out the money on a new pump.

I still get the code after slyfox bypass kit but I am guessing its because I did not install the block out plates due to rusty bolts. So, I install this OBDII diag scanner Then paid for Torque Pro to clear my faults until summer time.

 

[NeutronJon]

Alright, so this is something that I've been fighting. I originally wanted to go the "correct" way and had the parts replaced. P2440 came back, limp mode. I bought the hewitt-tech bypass. Still getting the code. Bank1 valve open. The only thing I can think is that the sensor is bad. The block off plates are in place so they can't be getting a pressure spike. This is what Hewitt suggested but I wanted to get some other opinions, or see if anyone else has encountered this. I've spent $2000 so far on this POS and am tired of clearing the code all the time. The weird thing, at least to me, is that is only comes on after several short trips. 16 degrees on the way to work and no problem. Stop at the gas station, then the store, stop to get something to eat, I need to clear it a couple of times. (I have a basic scanner, no battery disconnect). Any other ideas? Are the sensors part of the valve assembly?

Thanks

Awz,

P2440 is thrown when the system senses pressure pulses coming back into the SAS from the exhaust system. If the ECM sees this with the the pump off, it assumes that the valves are stuck open.

Since you have a bypass kit and the block plates installed, I would suspect that you have either a failed pressure sensor, or somehow the plate isn't fully blocking off the exhaust (maybe a hole or misalignment).

I think the easiest thing to do would be to replace the sensor with a constant voltage input to remove the pulsation signal it's seeing. If this is something you're interested in doing, let me know and we can work out what the desired voltage is and make a small circuit to do that.

Jon

 

[Awz]

NeutronJon
I am absolutely interested. I've printed off the PDFs you provided. So tired of clearing the codes all the time. Just let me know what I'm looking for, and as soon as I find a place above 15 degrees to work on it I'll get on it.

 

[NeutronJon]

NeutronJon
I am absolutely interested. I've printed off the PDFs you provided. So tired of clearing the codes all the time. Just let me know what I'm looking for, and as soon as I find a place above 15 degrees to work on it I'll get on it.

I would imagine the easiest thing would be to measure the voltage that the pressure sensor is sending to the ECM on a truck that isn't throwing the codes, and make your truck send that same voltage...

I haven't tracked down the location of where to measure that specific point on a wiring harness. Perhaps someone has the techstream software could pull the pressure / voltage out through the software a bit more reliably?

 

[NeutronJon]

NeutronJon
I am absolutely interested. I've printed off the PDFs you provided. So tired of clearing the codes all the time. Just let me know what I'm looking for, and as soon as I find a place above 15 degrees to work on it I'll get on it.

Here's another thing I came up with...

According to the factory service manual maintenance specifications, the normal output of the pressure sensor is 1.0 to 2.2 volts. You could make a simple circuit that would output a fixed voltage in this range to fool the computer into seeing a constant sensor output in the valid range.

I initially thought of connecting a few resistors to come up with the required voltage, but I think the circuit on this page would be more reliable. It also offers some protection for your ECM that my method would not have had.

1.3V Power supply - Electronic Circuits and Diagram-Electronics Projects and Design

In your case, the input would actually be 12-13.8 volts instead of 5, but the 1k resistor combined with the zener diode D1 will handle that and produce about 2V output (within the normal range of the sensor). Next, D2 will drop about 0.7V, giving you a nominal output of 1.3V which is in the low end of the band for the pressure sensor (which I'm assuming equates to depressurized). The small capacitor will help to filter out any voltage fluctuations on the input, which is also helpful since those would be interpreted by the ECM as pressure oscillations and send the code your getting now.

I would supply this circuit with the smallest fuse you can find. Personally I would use one of those twist plastic inline fuse carriers and put a 1/4 amp or 1/10th amp fuse in it.

Disclaimer: All of my work here is purely theoretical. I am not a licensed professional engineer and do not have access to Toyota's original design concepts. Reverse engineering carries some risk and my design has not been tested in any way. Anyone who uses this design assumes any and all liability for their vehicle. This application is released under the creative commons BY-NC license. Any person may use, modify, or otherwise update this design with attribution for non-commercial purposes.

The circuit diagram shown above is copyright Electronic Circuits and Diagram-Electronics Projects and Design.

 

[kai920]

P1441/1444

I hit 190k miles on the 05 v8 on our way to New Orleans this weekend. As soon as we started it up to come home to Houston the dash lit up and we went into limp mode, with codes P1441/1444-valves stuck open. Couldn't clear codes, and we had to get home, so I had to rent a uhaul and auto transport trailer to get it back to Houston from New Orleans. Great way to end the weekend, and perfect timing.

Lo and behold, I pull it off the haul trailer last night and while the dash lights are still on its running fine. This morning I got the shop vac sound under the hood. Ran it up to operating temp and then pulled the battery cable for about 20-30 minutes. All check engine lights and other dash lights went off. Drove it around all day with no issues. WTF?

 

[Atlanta_man]

Be thankful for this warning from your 4R. Next step will be either cheap or very expensive, your choice.

 

[Inv4drZm]

I hit 190k miles on the 05 v8 on our way to New Orleans this weekend. As soon as we started it up to come home to Houston the dash lit up and we went into limp mode, with codes P1441/1444-valves stuck open. Couldn't clear codes, and we had to get home, so I had to rent a uhaul and auto transport trailer to get it back to Houston from New Orleans. Great way to end the weekend, and perfect timing.

Lo and behold, I pull it off the haul trailer last night and while the dash lights are still on its running fine. This morning I got the shop vac sound under the hood. Ran it up to operating temp and then pulled the battery cable for about 20-30 minutes. All check engine lights and other dash lights went off. Drove it around all day with no issues. WTF?

Next time you might not be so lucky. It will probably do it again, so get the bypass kit.

 

[flipflopnfly]

. . . . . . . . .

HAVE FAITH BROTHER! The bypass is bulletproof. Proven time and time again(as long as ya'll install them correctly

Still sell'um.(I get a lot of emails just asking) email [email protected] w questions $45 shipped......

Installed this kit today as a precaution. Is the "oomph" sound shortly after startup the air pump? Because I didn't hear it after starting up.

EDIT: I guess it bears repeating, from slyfox75 - "Once you put in a bypass and [the valves] are closed they will never actuate again......you should be good FOREVER. That's why I try and "preach" to JUST DO IT. Take if from some of these guys.....its WAY easier to do bypass early than to wait til you begin having issues.
Reach me at [email protected] for questions. That was from 10/29/2015 - 10/30/2015, posts 122 and 123 in this thread.

 

[blackoutt]

I PM'ed him through here as well although he doesn't frequent this forum a day later we had conversed paid and received tracking info! It's a pretty simple kit, easy to install and make look tidy, and never have to worry again.

 

[slyfox75]

Hey guys! To be clear, the bypass will in essence "kill" the AIP system.
If your valves are either closed(normal state) OR STUCK closed, the bypass is all you need. AND better yet do it BEFORE your dash lights ever light up.
To be clear, if your valves are stuck open....AKA limp mode.....the bypass will defeat the AIP system.....BUT will not defeat the safety feature for backpressure from the exhaust manifold. So you will still get limp mode and need plates.

I've had quite a few people that get stuck open valves but then reseal/close on their own......its a crapshoot. The longer you wait from first occurrence it seems the harder it is to get them to close on their own.

Another thing is you can do a bypass without the blockoff plates, but NOT vice-versa.

Kits are still $45 via paypal to jeffcole75 at gmail if needed.

 

[flipflopnfly]

Yeah, I got tired of worrying and ordered the kit. Better safe than sorry. May be the best $45 I've ever spent. Can't go into limp mode towing a trailer out in the boonies.

 

[CXS]

Yeah, I got tired of worrying and ordered the kit. Better safe than sorry. May be the best $45 I've ever spent. Can't go into limp mode towing a trailer out in the boonies.

My thoughts exactly, cheap enough & easy to install. Peace of mind...

 

[mpyle]

Preventative maintenance that's cheaper than your wife's haircut. Any questions?

Sent from my SAMSUNG-SM-N910A using Tapatalk

 

[drbyrdman]

My pump just went out and Toyota wont warranty it

 

[olegrad]

Anyone having any luck contacting slyfox via gmail? Haven't heard back. Hoping to do this as preventative maintenance.

 

[mpyle]

Anyone having any luck contacting slyfox via gmail? Haven't heard back. Hoping to do this as preventative maintenance.

Yes always responded to all of my emails and he will to you too.

Sent from my SAMSUNG-SM-N910A using Tapatalk

 

[Brian3676]

Been running the kit from Slyfox on my 08 4Runner for a while now. Working great.