Active Grill Shutter (AGS) - Alert Message and Fix

[dbentley]

Hi everyone,
I’m new to the group and recently installed a Barricade Stubby bumper with a winch on my TRD Sport. I cut out the lower portion of the factory grille assembly and bumper.
Since then, I’ve run into an issue with a persistent alert message indicating a malfunction with the active grille shutter system. I’m trying to figure out whether the problem is caused by the shutter itself or by the relocation/positioning of the sensor after the modification.
I’ve ordered a shutter delete, but I’m not convinced that the shutter is the root cause—it may actually be related to the sensor placement.
Has anyone here done a similar bumper install and dealt with this issue? If so:

• How did you handle relocating or modifying the sensor?
• Did you use a shutter delete, and did it resolve the alert?
• Any tips or best practices to eliminate the warning message?

I’d really appreciate any insight from those who have already tackled this.
Thanks in advance!

Sponsored

 

[dbentley]

 

[Ruckus]

I did a shutter delete when I installed the SDHQ grille light mount. It included a little 3D-printed bracket to hold the shutter actuator, but the rest of the shutter assembly was removed.

I have not had any errors or messages regarding the shutter since doing the install about a month or so ago.

Here is the kit I used, but it includes the light mounts - https://sdhqoffroad.com/products/2024-toyota-tacoma-bumper-light-mount

You can see in the images that it's just 2 small pieces of 3D-printed material that connect to the shutter actuator.

Did you disconnect your negative battery terminal while you were working on the truck and had the grille shutter unplugged?

It's hard to see in your photos, but the shutter actuator needs some kind of resistance and limiter to trick it into thinking the shutter assembly is still connected. What exactly did the bumper kit include that interfaces with the actuator?

 

[dbentley]

Thanks for the response, really appreciate your help. I did have the battery unplugged when I took it apart. And I did have room to put the shutter back in complete. I think the problem I have is that I zip tied the sensor out of the way instead of putting it in a more open spot.

Did you still connect the sensor back on?

Going to pull it apart and see if I somehow damaged the wiring when I put the grill back in. And check to see if I am getting any voltage to the actuator.

This has me really stumped. Because I really did not change anything on the shutter or actuator. Just the sensor location.

Getting the shutter delete from CAtuned this weekend, just in case I have to remove the whole shutter.
https://catunedoffroad.com/products...4runner-shutter-delete?variant=47093237678339

 

[Ruckus]

When you say sensor, do you mean the shutter actuator? The little motor that is attached in the middle of the shutter assembly that the wiring harness plugs into?

 

[dbentley]

there is an active grill shutter sensor that I relocated, someone else had to relocate it as well.
https://www.tacoma4g.com/forum/threads/grill-shutter-malfunction-issue.5048/

 

[Ruckus]

Interesting - what year is your truck?

I have a 2025 SR5 and there is no sensor, unless I totally missed it. But I don't see how I could've deleted the entire grille shutter assembly without having to touch that sensor if it did exist.

 

[maxx075]

I could be 100% wrong, but that just looks like a generic ambient air temperature sensor. Which I'm sure is used by the CAN for determination of the orientation of the shutters.

 

[Ruckus]

I could be 100% wrong, but that just looks like a generic ambient air temperature sensor. Which I'm sure is used by the CAN for determination of the orientation of the shutters.

Wouldn't the position of the shutter actuator be what relays the position of the shutters? From what I understand, which isn't much, that is why these 3D printed frames are needed to delete the shutter. It adds resistance to the actuator motor to trick it into thinking the shutters are either open or closed.

 

[maxx075]

Wouldn't the position of the shutter actuator be what relays the position of the shutters? From what I understand, which isn't much, that is why these 3D printed frames are needed to delete the shutter. It adds resistance to the actuator motor to trick it into thinking the shutters are either open or closed.

I'm sure the position is relayed back to the CAN somehow. What I'm saying is that the picture OP posted doesn't look like any type of "grille shutter position" sensor.

And what I meant with the location of the shutters in regard to that sensor is that the ambient air temperature is mixed into the data to determine how the actuator should rotate (open or close) based on engine temp, air temp, etc.

 

[dbentley]

Yes, the sensor is for the ambient air. not a position sensor. This is a 2025 TRD Sport

 

[dbentley]

I tucked it away when I zip tied the wiring harness. Going to bring it out tonight and place it in an open area to see if that can clear the fault warning.

 

[dbentley]

Just want to say thank you to you all, this is great!

 

[dbentley]

All, somehow the fuse tripped. All good now, no malfunction messages.
Traced the entire wiring harness last night to ensure I didn't accidentally clip a wire. And ended at the fuse box. I should have started at that end......
I did however replace the sensor to an open space, I had it buried before. I still think that was part of the problem. Not sure how the fuse tripped. I did disconnect the battery when I did the work.

Problem solved and no CEL message!

 

[dbentley]

I truly feel like a grill shutter expert now! Should have made a video.

Sponsored