I know a lot of '06-'07 owners bypass the SAI system when it starts to go bad, I'm going to try to fix it. (1 Viewer)

[Rick Kane]

Nice write up I found my SAIS filter is completely gone so need to do this. Have a reman's starter also needing to go into my old starter, and will need to buy some of the other accessories like you had here.

For your heater T's i'd highly recommend you replace those Worm clamps, the problem I find is the many open holes in the circle clamp part that grips the rubber hose. They will do more harm than good, as they eat into the soft rubber material of the hose. Over time with the heat cycles, it'll cause the rubber to harden with those imprints. And over extended time it will start cracking.

If you thought replacing the clamps and T's were a pain in the ars, replacing the hoses too especially the bottom points where they clamp on, is not a fun job.

Thanks take123. I actually found that replacing the hoses for the heater Ts (even at the bottom points) wasn't that hard if you already have the intake manifold off, which I did for the SAIS job already. Anyway, back to the trenches...I'm going to keep fighting this project and we'll see what we get. Cheers.

 

[Rick Kane]

This is copy from FSM. May be a short or bad VSV.
P0412 Secondary Air Injection System Switching Valve "A"Circuit
1. Open in air switching valve drive circuit
2. Short between air switching valve circuit and +B circuit
3. Short between air switching valve circuit and body ground
4. Air injection control valve
5. Air switching valve
6. ECM

Thanks 2001LC. I really appreciate the quick reply. Would have thanked you sooner but I was "playing" with this issue some more yesterday too as I'm running out of time to get this project done so that I can get the old LC100 past the darn emissions testing here and get this baby re-registered. Very cool of you to send me this bit from the FSM. I'm starting to think that the issue might be pieces of the old air pump assembly's foam filter stuck somewhere within the switches or hoses of this wonderful SAI system - maybe at one of the VSVs. Man, I hope the issue is not the ECM...

 

[2001LC]

Toyota has a TSB out. That said we must replace every part in S.A.I. Which I thought ridiculous. But it do to what I found in my first. Which was the entire system was dirty inside. Eventually I found it to be debris in the pressure sensor, kept causing a DTC. Which the pressure sensor comes with main switch.

Pressure switch test is near useless if debris in it. FSM has check at ECU behind glove box, for current. But this doesn't tell us pressure. There are a number of test. Easiest is a the VSV. The two vacuum hoses coming from 2nd switch off the rear water bypass. It's been years since I've done these test, so consult the FSM. You do need to have a 2006-07 FSM, to work on a VVTi engine.

 

[Rick Kane]

Toyota has a TSB out. That said we must replace every part in S.A.I. Which I thought ridiculous. But it do to what I found in my first. Which was the entire system was dirty inside. Eventually I found it to be debris in the pressure sensor, kept causing a DTC. Which the pressure sensor comes with main switch.

Pressure switch test is near useless if debris in it. FSM has check at ECU behind glove box, for current. But this doesn't tell us pressure. There are a number of test. Easiest is a the VSV. The two vacuum hoses coming from 2nd switch off the rear water bypass. It's been years since I've done these test, so consult the FSM. You do need to have a 2006-07 FSM, to work on a VVTi engine.

Yes, I've got that wonderful TSB in-hand too. Where is the pressure sensor? Is it part of the Air Switching Valve Assembly (25710-50022)? I've gotten a 2-day subscription to the FSM, so hopefully I can pull down what I need before I run out of time.

 

[zgfiredude]

Yes, I've got that wonderful TSB in-hand too. Where is the pressure sensor? Is it part of the Air Switching Valve Assembly (25710-50022)? I've gotten a 2-day subscription to the FSM, so hopefully I can pull down what I need before I run out of time.

Holler if you need some FSM lookup assistance, I have hard copy all 4 volumes of the '06/'07 manuals.

 

[aging fleet]

Well damn...

Not only did the new SAI pumps (small ones, first two listed below) fail to resolve my error codes, even after installing a new Air Pump and Air Switching Valve Assembly (and new hoses) I'm still receiving error codes C1201 (Engine Control System) and P0412 (Secondary Air Injection System Switching Valve "A" Circuit".

@Rick Kane, sucks to hear you've done so much and are still having issues. Mine has been trouble free since I wrapped up the SAI project and I hope you get to that point soon too. Just keep at it, you've (hopefully) eliminated all the expensive stuff, likely it's something small that's continuing to drive the issue.

 

[2001LC]

Yes, I've got that wonderful TSB in-hand too. Where is the pressure sensor? Is it part of the Air Switching Valve Assembly (25710-50022)? I've gotten a 2-day subscription to the FSM, so hopefully I can pull down what I need before I run out of time.

Yes.
Black plastic sensor with two 10mm bolts holding it on A.I. #1 SW. The three wire housing block connect to it.

I was going replace just the pressure sensor as a test, to confirm it was the culprit. But looking into the 1# SW, I could see staining/dirty valve. Which was due to no filter in A.I pump. Not wanting to pull intake manifold again. I just replace the #1 SW w/PS sensor, with a used one I had. As I recall: I was getting P1445 & P1442. I had found nuts on stud of to exhaust manifold the air pipe from the #2 SW, was damage and loose (air leak). Found one of the #2 SW to be aftermarket (NAPA). Many air leaks before, at and after CAT (aftermarket). I had to work through alot. After all worked through/fixed and my filter mod installed. The last was replacing #1 SW w/pressure sensor. I've not had any issue since (~5 years)

Pressure sensor circled in red.

 

[Jack90210]

I'm putting together a parts list of items to replace under the intake manifold (basically everything: cooling, starter, SAI) and this thread was super helpful for the SAI parts! Thanks y'all.

 

[2001LC]

If filter is in place, within the SAI pump (BLOWER). You can just remove the filter from it, and add the replaceable filter mod. 9 out of 10 times, we don't get any DTC after the filter mod. The 1 in 10 we do. Usually ends up needing, main SW replaced. Due to dust dust entering system. So replacing main SW cost extra, but save pulling intake manifold again in that 1 out of 10.

The filter mod, reduces long term maintenance cost. If filter mod not done, pump will need replacing periodically. Sinice all SAI pump filters, will fail. ALL!

 

[zgfiredude]

I'm putting together a parts list of items to replace under the intake manifold (basically everything: cooling, starter, SAI) and this thread was super helpful for the SAI parts! Thanks y'all.

And you're going to share said parts list for all your friends, right?