charlie_fong

I have a 2008 Tacoma 2.7L with an MIL P2441. From what I'm reading in the FSM, these are the possible issues:

- Air switching valve (ASV)
- Open or short in ASV circuit
- Vacuum hose (ASV pressure sensor)
- Air injection hose
- Pressure sensor
- Pressure sensor circuit
- Air Injection Control Driver (AID)
- ECM

The vacuum hoses are all connected and properly routed. Electrical connections are connected and visually seem fine. I checked the ASV inlet for soot and moisture, but it appears to be somewhat clean(signs of dirt, but no soot from exhaust).

For the heck of it, I tried testing the air pump. When I connected the battery to the pump, it sparked, spun for a second and then stopped. Now it seems it won't turn on. I connected the positive and negative leads correctly. I took the pump apart and there appears to be no damage. Did I test this air pump incorrectly?

charlie_fong

So I reinstalled the air pump and it turned right on no problem. The issue wasn't with the pump, but with the wire leads I used. It seems that one of them melted in the insulation.

Anyway, I did some more tinkering and pulled out the ASV to diagnose. Here are the steps I followed.

Turns out the ASV valve was stuck shut from excessive soot and burnt oil(forgot to mention engine is burning a bit of oil).

I reset the MIL and drove it for four miles. So far it hasn't turned back on. I'll know for sure tomorrow morning when my dad goes to work.



Opened up the ASV. Very dirty.



Do not unscrew the reed valve bolts! I ended up breaking one and found out it wasn't mounted to the ASV. You just pull it off. Anyone know the size of that bolt and how to remove the rest of it?



Bottom of the ASV that goes to the exhaust. Yuck..



Cleaned most of the gunk off the ASV. Connected it to a 12v source and it opened up smoothly. Sorry about them toes there. My dad didn't feel like wearing shoes.