2005 V8 engine - Gaining access to the secondary air pump circuit

[slyfox75]

Ah OK, I was going to say......I think the ECU does a "is the pump even present check" when it starts out. Probably checks resistance to ensure its not shorted but not open circuit either. This prevents people from just unplugging the entire system. Do you know, did that cable go to the pump or the Air Switching Valve?

 

[wbwatson]

My understanding is that it goes to the pump but I can’t say for sure. It ties into a larger harness so I can’t trace the specific wires.
My wife hoped in the car this morning and it started up with no CEL. Of course she didn’t let the key sit in the “on” position prior to starting so I assume the issue is still present. I am going to give it some time then test it again. Maybe it will start behaving normally after all of the readiness monitors reset.
If is still acting up this weekend I will try removing the bypass to see if it still throws a 0418 prior to start up.

 

[07V8]

In order to avoid starting yet another secondary air pump thread I am going to piggy back on this as it appears to be the most one this topic.
A couple of weeks ago my 2005 V8 Sport threw a 0418 (Secondary Air Injection System Control "A" Circuit) and 2445 (Secondary Air Injection System Pump Stock Off Bank 1). These codes were also accompanied by sporadically getting limp mode. I unplugged the air pump driver and contacted Slyfox (who is a really good guy BTW) about installing his kit.
I have now installed the kit and it appears to have fixed the 2445 code, but I still get a 0418 under rather odd circumstances. I only get the 0418 when the key is in the "on" position, without the vehicle running, for more than what seems to be a couple of seconds. This happens when it is hot or cold. I can even let it sit in the "on" position without the engine running, clear the codes, and they come back instantly. On the other hand, if I start the vehicle without letting the key linger in the "on" position I do not get a code. It seems like the computer is trying to check the status of the pump driver or something else prior to start up and it sees something it doesn't like. Any thoughts?

The only reason you're in limp mode is because the valves are stuck open. If this is the case, the bypass will not keep that from happening. You need the valves to close or you need to install the block off plates.

 

[wbwatson]

It's not in limp mode anymore. I lucked out and got the bypass installed with the valves closed.

 

[wbwatson]

I temporarily removed the bypass to confirm that it is NOT causing the 0418 code. It still throws a 0418 code while in the on position without the bypass. The 2445 code has not come back so I believe the bypass is functioning as designed.
It looks like I just waited too long to get bypass so I will have to replace the air pump prior to getting it inspected this year. I still plan to leave the bypass installed after I replace the pump to prevent more issues with the system. It is painful replacing a part that I am going to immediately disable, but it looks like that is the only way to pass inspection.
Moral of the story.....I should have reached out to Slyfox sooner!

 

[snowboardwcu]

Awesome writeup. To the point. Need to take precautions myself to prevent doing this, but happy to see this effort thanks

i did not take my own advice. sucked a bunch of sand into the AIP and now the engine is a shop vac on startup.

slyfox kind enough to get one ready for me over the holiday weekend.

people's thoughts on even bothering to clean it out? install bypass and move on with my life?

 

[Direwolf82]

Ah OK, I was going to say......I think the ECU does a "is the pump even present check" when it starts out. Probably checks resistance to ensure its not shorted but not open circuit either. This prevents people from just unplugging the entire system. Do you know, did that cable go to the pump or the Air Switching Valve?

I was just curious if it would be possible to plug a resistor of the correct rating, as in same resistance as the pump, into the harness and just leave the pump totally disconnected? Would that be a possibile fix to avoid the stuck valve situation?
I just picked up my 03 limited v8 and want to get this squared away before I have an issue.

 

[AuSeeker]

I was just curious if it would be possible to plug a resistor of the correct rating, as in same resistance as the pump, into the harness and just leave the pump totally disconnected? Would that be a possibile fix to avoid the stuck valve situation?
I just picked up my 03 limited v8 and want to get this squared away before I have an issue.

The 2003 V8 doesn't have a secondary air pump or the valves associated with the pump, they only started having them on the 2005 and onward V8s, so you don't have to ever worry about it at all!!

 

[Scott1978]

I've been reading through these forums. I had several codes on my 2005 4runner v8. The bypass kit cleared the codes except for the P0418. I'm not quite following what the reason for that particular code. Does it mean I need to replace the air pump? While searching online that code issues could be:

A.Faulty Air Pump inoperative
B.Air bypass solenoid harness is open or shorted
c.Air bypass solenoid circuit poor electrical connection

Are any of these able to test without taking the intake manifold off? For instance B or C? Where are these located?

 

[slyfox75]

If you have 0418.....you can try disabling bypass and starting truck to see if you can get the pump to spin a little. Then hook up bypass again and see if you got the armature of the blower in a position that removes that code(this is all "luck" and depends on how bad the blower is).

Second thing or you can skip right to this, is to order a Pump Replacement Pack from Hewitt Tech that plugs in where your pump does and tricks ECU into thinking the pump is fine. (MUST have a bypass installed to go this route tho.....which you do.....just putting this here for others that are reading)

0418 isnt going to hurt anything. You can run forever with it.....but the CEL will remain on obviously.

 

[Gene44]

Just bumping an old thread with my recent results.
I was getting the feared P2445 code with my CEL. Inspection overdue, panic time. Short story, ordered the bypass kit from Slyfox75, got it 3 mailing days later. Took 8 drive cycles and 100 miles but finally got a "ready" on secondary Air and passed inspection. Pump was never commanded on so it took a while for ECU to show ready.
I have a 2008 4runner Limited.

It is worth noting this is an excellent well thought kit from Slyfox75. Instructions are clear with good pictures. My profound thanks to Jeff.

 

[Hitmanhink]

Clean the foam out of the control valve. After using compressed air and carefully scraping away the existing foam, I used non-chlorinated brake cleaner to spray inside the control valve body followed by drying it out with compressed air. Several attempts might be necessary. The key is to remove ALL of the foam as best you can.

It is strictly my opinion but I believe Toyota used the same foam to seal the air pump as was used inside the control valve. Look closely at the similarity in texture between the pics. The same sticky consistency was observed in material with both the control valve and secondary air pump seal.

NOTE: I cleaned all of the gasket surfaces with brake cleaner sprayed onto a paper towel. All of the intake plenum rubber was cleaned in the same manner, making sure there is a clean surface for the intake to seal to once it is installed to the engine block.

[MENTION=77155]bergs[/MENTION] I know this is a very old thread but what a great write up thank you so much!

I’ve not seen anyone go to such lengths to keep the system functioning.

Has anyone removed the foam preemptively when installing a new pump and valve?

I’ve noticed on other vehicles, such as the 5th gen, where the SAIS is more accessible, removing the foam or modifying with an air filter is much more of a common approach. But can anything like that be done on our 4th gens 05-09’ ?

 

[1E9v8]

Same question as Hitmanhink
“ Has anyone removed the foam preemptively when installing a new pump and valve?

I’ve noticed on other vehicles, such as the 5th gen, where the SAIS is more accessible, removing the foam or modifying with an air filter is much more of a common approach. But can anything like that be done on our 4th gens 05-09’ ?”

I’m about to replace the secondary air pump on my v8 4Runner and was curious if the uni filter mod will work under the intake and if anyone else has tried this mod on the v8.
Thanks in advance