Not a Tacoma but a Venza Question

Sorry if I'm posting in the wrong area.. My wife's 2014 Venza (3.5 V6) randomly sounds like a motor running while the car is off. It doesn't do this all the time but I've heard this more than a few times. Seems this motor of some sort will run for like an hour maybe and then stop. Then I may not hear it again for months.... though I'm not "camping out" beside the car listening for it either. I've thought maybe it is a fuel pump, but it doesn't make sense when the car is off. Doesn't seem to be a major problem, battery doesn't seem to be drained. Just been wondering WTF this is.
Anyone else have a Toyota do this?

https://youtu.be/GmZSb5y6_Mk?si=ayKAaWKh2lObtCBN

 

EVAP. Normal.

 

Most likely the EVAP test running, it runs 5-11 hrs after the engine is turned off.

From the FSM:

1. Key-off monitor

This monitor checks for EVAP (evaporative emission) system leaks and canister pump module malfunctions. The monitor starts 5 hours* after the ignition switch is turned off. At least 5 hours are required for the fuel to cool down to stabilize the EVAP pressure, thus making the EVAP system monitor more accurate.

The leak detection pump creates negative pressure (vacuum) in the EVAP system and the pressure is measured. Finally, the ECM monitors for leaks from the EVAP system, and malfunctions in both the canister pump module and purge VSV based on the EVAP pressure.

HINT:

*: If the engine coolant temperature is not less than 35°C (95°F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not less than 35°C (95°F) 7 hours after the ignition switch is turned off, the monitor check starts 2.5 hours later.

 

Does that motor have the AIP system?

The air injection pumps can run at anytime the engine is off.

 

It shouldn't, the Secondary Air Injection System (SAIS) (if equipped) only runs on a cold start for 30-60 secs and some run a few seconds at key off to purge the valves.

 

That is most definitely your evap pump running it's system check as it should. I was working on my truck the other day when my evap pump started humming away

 

I'm only going by my Tundra(s).

The pumps on the Tundra can turn on 6 hours after you are done running the trucks. It's very odd going out to the garage to grab a beer and you hear those pumps spool up.

 

You sure it was the SAIS pumps and not the EVAP test running? I've never heard of the SAIS running with the engine off, there would be no point in running the system with the engine off as it's only purpose is to pump fresh air into the cats during a cold start to help them come up to temp and lower cold start emissions.

 

The tundra's had a problem with moisture developing in the pumps as well as the valves. The -07thru14 years would rust the pumps and valves. To help with this, the AIP systems were programmed (flashed) to run at random times outside of cold start ups.

Sorry to derail the thread, I know this was intended for the Sienna vans.

 

Interesting, I agree with Dm93 that the smog pump is to warm the cats... thats an interesting "fix" if it does in fact randomly pump air to rid it self of moisture.. I would imagine it happen sooner than 6 hours after the vehicle is off because when it gets to -30* even the moisture will freeze pronto

 

Interesting, the 2012 Tacoma V6 had that issue too. The system was updated in 13 to run the pump for a few seconds at engine shutdown but it doesn't run anymore after that.