ACIS: add push button switch for semi-manual operation?

After disconnecting the ACIS, low-speed, low-demand (ie, around town etc) shifting is waaaay smoother as is accelerating from a stop. But power takes a huge hit at higher rpm.

What I’m wondering is if I can insert a switch to deactivate the ACIS on demand. And would it be a momentary or toggle? Or, is the circuitry more complicated than that?

 

NOTE: I have NOT done any experiments with ACIS, so any of my comments are theoretical only.

I have read a few threads on the ACIS, and from what I understand the truck ECU does not appear to monitor the ACIS system so you can just disconnect the ACIS motor.

There are quite a few options for switches that would work.
For a toggle type switch, you would want an OFF-ON switch that is latching in both positions (not momentary).
Another option is a push button switch that is latching in OFF and ON.

MOST LIKELY, you will just cut one wire running to the ACIS and route it thru the switch.

 

That’s what I’m thinking also, though I think I’ll get the harness connectors and make a simple harness to attach in-line. One thing I’m not sure of though is if the actuator needs constant current in one particular position, and even if if it did, I’m not sure this would matter.

Also, is using a relay the right way to to this?

 

Probably not worth the effort to use a relay, because then you need to add power source as well.

You just want to cut one wire at any location between the actuator and ECU (using a Plug and Play connector, or directly in the harness). Just route it thru the switch.




you could splice in at the V3 connector (at the actuator), but it is USUALLY hard to get both the female and male connectors (but not necessarily impossible).
Or could make a PnP harness and connect at the IH1 connector or the ECU connector.... (but ECU will have a billion connections)

 

https://www.corsa-technic.com/item.php?item_id=968
https://www.corsa-technic.com/item.php?item_id=996

 

Any idea what to select from the options? Size etc…

 

Since you are adding a switch (long wire run to cab), I'd use the largest wire terminal and seal.

 

@caribe makaira do you think it's a good idea to place a switch in series with ACIS? The reason I ask is because it's a motor which can pull some amperage. I do not know the current draw of that motor, but I do know the wire is approximately 24 awg. I also understand that some switches can support that load, but I'm thinking more along the lines of safety.

Something to point out is the polarity is reversed when the valve is moved in the opposite direction. I just want whoever may do this install to be fully aware that, depending on the circumstance, the "negative" leg of the switch could be energized, even if the switch is in the off position. Use insulated connectors on both if doing this modification.

Another thing that I'm curious about:
I'm pretty sure the gear internal of the actuator will move freely if disconnected. Could this pose a problem while driving? I do know that without a load, that gear should be able to move with little to no resistance. In my mind this makes me think that the valve could move around. Of course, I don't know how airflow will affect it but I hope someone can chime in.

 

I wouldn't mess with any internals of the engine. OP just wanted to know about placing a switch.

 

And I didn't mention adjusting any internals either. That connector goes to the actuator, does it not? That actuator controls a motor that rotates a gear which opens and closes the ACIS valve.

 

Things like this are why ask about using a relay.

 

Can anyone confirm this? I know a couple people here have had to replace this valve. I’ll see if I can find out who and tag them. Off to work now.

 

One of the ways to check that the actuator works correctly (per the repair manual) is to disconnect the connector and manually manipulate the gear. It should move freely. The motor with a load will be difficult to turn, but without a load it can move easily.

I'm not suggesting you do anything to the internals. I'm saying that with that connector disconnected (even via a switch) there will be no load on that motor which means that the ACIS valve is free to move around as it pleases. My concern was what would that valve do with the airflow inside of that manifold? It may do nothing, or it may flap around like a flag in the wind. That's what I'm curious about.

Just food for thought. Maybe someone else can chime in on that. I know this valve isn't new, so maybe it's a common modification?

 

@lstrople @333dzl

Do either of you know if the quote above is true/false? Wondering if you noticed while you had yours out…

 

Bump

 

I don't have anything to add to actually modifying the circuit with a switch/relay but I think I remember there being some discussion about this actuator possibly being added to the vftuner capability at some point in the future. I think the discussion was if there was anything to gain or if Toyota tuned it for max torque. If I find that discussion I'll link to it here

 

ACIS is tunable in VF. Unless you are referring to disabling it completely?

 

Ok. Vf doesn’t seem out of the realm of possibility based on what little I know about it. I haven’t been on tw much in a couple of years so I’m not up to speed on what’s available other than ov.

 

I don't believe it was available parameter when I last made any ECU adjustments but it's good to know that it is now. Wouldn't it be possible to just set the value to whatever the closed position is and use that across the entire table(s) effectively disabling it? Or better yet, do that under a certain rpm/load threshold to preserve top end?

 

It has been there since at least October of 2020, not sure how long before then, as that is when I finally made the purchase. It's one of the common edits people make, changing the value from 3600 RPM's to 3400 RPM's. I imagine that if the value is raised enough, it can prevent it from actuating at any speed, but I have not tested that so I assume no responsibility if someone does and SHTF.