[adavidw]

So if 2 or 3 of you would like to send me a new OEM (dealer sourced) actuator with a return postage label, I will modify the actuator with diodes at no cost and return it to you.

I volunteer. I've been having the problem on my 2020 for at least a couple of years now. I had been finally meaning to replace it this summer, but then the van went to the dealer for the 03A transmission recall where it's been sitting waiting for a transmission for the last couple of months .

I'd be happy to send you a part to fix and will install it as soon as I get the van back and will commit to updating the thread regularly to report status.

 

[drocketman]

OK, sending you a PM.

 

[ShiftyP81]

My "fix" is still working fine as of 2 days ago, but I just traded in my 2018 PacHy Limited (AST) for a 2025 PacHy Pinnacle. My 2018 had the oscillation problem severely for 6 years, but neither of my Pinnacles have the problem. I don't want my "fix" to be a victim of forum memory loss, so I want to help solve the Blend Door Actuator Instability/oscillation/pumping-gear-turning noise for other users.
So if 2 or 3 of you would like to send me a new OEM (dealer sourced) actuator with a return postage label, I will modify the actuator with diodes at no cost and return it to you.
It will be modified so that it is plug and play and will fit with no mods just like the original. It will have no external wiring changes like my prototype had. You can then install it or have it installed to replace your current oscillating actuator, and then please periodically post here whether the oscillation is gone or returns. Coordinate on this thread with me publicly so there will be no confusion of too many people sending me stuff. If this trial is successful, we'll go from there.

Hi i believe we are having this issue. Knocking sound from passenger side dashboard area. I have not taken out the glove compartment and panel yet. I'm a big guy and from the sounds of it, replacing this is a nightmare for people with the little space.

Can you explain your tweak and how this helps? We have a 2023 Pacy Hybrid but are already close to 47,000 miles so are in our extended warranty period already.

 

[adavidw]

Can you explain your tweak and how this helps?

I'm not drocketman, but I can explain in layman's terms. The car sends some voltage to this blend door actuator to move the blend door to it's middle position, and waits to see a certain voltage on the circuit that indicates that the actuator is in the right place. The overall solution is a bad design where the actuator moves a little too fast for the car to reliably sense that position. Whenever the car doesn't get the position right, it keeps just sending the voltage until it does sense that the actuator is in the right position, or until it gives up after a few minutes. Once the actuator wears over time, it can move a little faster, making it more likely to miss the right position, making the car move it longer and accelerating the wear. Over time, the potentiometer (the part that actually changes the voltage so that the car can tell what position it's in) wears out meaning the voltage never gets to the right level for the car to sense.

Chrysler could have designed the circuit or the actuator better, or designed the software to handle the situation better, but since they're not making any changes here, drocketman has come up with the ingenious solution of essentially slowing the actuator down by soldering a couple of diodes into the wiring of a new, not worn out actuator. That will make the car sense the position more reliably and keep it from wearing out the new actuator. Without this fix, you can replace the actuator and fix the problem for a time, but it will most likely come back within a few months to a few years.

(His full explanation of the fix is here)

 

[BriPac]

I'm not drocketman, but I can explain in layman's terms. The car sends some voltage to this blend door actuator to move the blend door to it's middle position, and waits to see a certain voltage on the circuit that indicates that the actuator is in the right place. The overall solution is a bad design where the actuator moves a little too fast for the car to reliably sense that position. Whenever the car doesn't get the position right, it keeps just sending the voltage until it does sense that the actuator is in the right position, or until it gives up after a few minutes. Once the actuator wears over time, it can move a little faster, making it more likely to miss the right position, making the car move it longer and accelerating the wear. Over time, the potentiometer (the part that actually changes the voltage so that the car can tell what position it's in) wears out meaning the voltage never gets to the right level for the car to sense.

Chrysler could have designed the circuit or the actuator better, or designed the software to handle the situation better, but since they're not making any changes here, drocketman has come up with the ingenious solution of essentially slowing the actuator down by soldering a couple of diodes into the wiring of a new, not worn out actuator. That will make the car sense the position more reliably and keep it from wearing out the new actuator. Without this fix, you can replace the actuator and fix the problem for a time, but it will most likely come back within a few months to a few years.

(His full explanation of the fix is here)

I replaced mine a few years back with a cheapy $20 aftermarket one. It's not the end of the world but skinny fingers help just drop the glove box cover it's to the left and use a 5.5 mm socket you can practically twist the 3 bolts out by hand then just twist them back in by hand you don't need to get a socket wrench back there

 

[ShiftyP81]

I replaced mine a few years back with a cheapy $20 aftermarket one. It's not the end of the world but skinny fingers help just drop the glove box cover it's to the left and use a 5.5 mm socket you can practically twist the 3 bolts out by hand then just twist them back in by hand you don't need to get a socket wrench back there

Thanks. Skinny fingers on never been accused of lol so this is not looking good for me. I've been told I have other sizes though.

What if you don't fix it? Anything other than annoying noise sometimes?

 

[adavidw]

What if you don't fix it? Anything other than annoying noise sometimes?

The actuator could continue to wear to the point where it can't be used for it's intended purpose of putting the recirc door to one position or the other and so you won't have control over whether your climate control recirculates the air. The noise will then become present not just when you stop the car but also while you're driving.

There's speculation in this thread that the actuator moving after you shut off the car is an extra strain on the 12v battery making it more likely to run down. There's additional speculation about possibly interfering with software updates or the car's proper shutdown tasks. I don't know about that, but just making sure the AC works properly is enough for me to want to do the fix.

 

[BriPac]

Thanks. Skinny fingers on never been accused of lol so this is not looking good for me. I've been told I have other sizes though.

What if you don't fix it? Anything other than annoying noise sometimes?

Just get it fixed as was mentioned the sound can be quite annoying and it can literally go on for hours slowly draining your battery as a in a big parasitic draw... Another hint the furthest one back of the 3 bolts is kind of hard to get to if you just left that one out and did the upper and lower bolt it would stay in there just fine finger tight with the 5.5mm socket.
I once knew a guy who owned an Italian restaurant named skinny fingers😅

 

[SouthFLPacifica]

The actuator could continue to wear to the point where it can't be used for it's intended purpose of putting the recirc door to one position or the other and so you won't have control over whether your climate control recirculates the air. The noise will then become present not just when you stop the car but also while you're driving.

There's speculation in this thread that the actuator moving after you shut off the car is an extra strain on the 12v battery making it more likely to run down. There's additional speculation about possibly interfering with software updates or the car's proper shutdown tasks. I don't know about that, but just making sure the AC works properly is enough for me to want to do the fix.

A harbor freight cheap thumb ratchet will REALLY come in handy. If I remember correctly when I replaced mine, I also had to buy a little 5.5mm socket.

The $20 Dorman actuator I bought from Amazon has been fine ever since.

 

[BriPac]

A harbor freight cheap thumb ratchet will REALLY come in handy. If I remember correctly when I replaced mine, I also had to buy a little 5.5mm socket.

The $20 Dorman actuator I bought from Amazon has been fine ever since.

I got you beat I think I paid $16 Amazon for mine going on 4 years now.....

 

[cookid]

I followed @drocketman’s 6 diodes solution, and was able to put all inside the case of the Amazon $15 Dorman actuator. Did it for my 2018 PHEV 2 weeks ago, and it’s still going well. I hope it’ll be my last replacement. Every time it scratches my hand badly.

The procedure is simple:
1. Open the case. Try not to break the plastic clamps.
2. Unsolder motor’s blue wire from the circuit board which connects to pin 6.
3. Solder 3 pairs of 1N4001 based on drocketman’s diagram. Put them in a heat shrink tube.
4. Solder one end with the blue wire.
5. Solder the other end in the hole connected to pin 6, where the blue wire was connected to.
6. Carefully place the diodes in the vacant space and make sure not to shortcut anything or interfere with the gears.
7. Close the case.

Thank you @drocketman for the ingenious solution!

 

[cookid]

BTW, I took a picture of the failed Dorman actuator. The resistive film is indeed worn out, presumably from the oscillations. This one only last for <1.5 years.

 

[drocketman]

I followed @drocketman’s 6 diodes solution, and was able to put all inside the case of the Amazon $15 Dorman actuator. Did it for my 2018 PHEV 2 weeks ago, and it’s still going well. I hope it’ll be my last replacement. Every time it scratches my hand badly.

The procedure is simple:
1. Open the case. Try not to break the plastic clamps.
2. Unsolder motor’s blue wire from the circuit board which connects to pin 6.
3. Solder 3 pairs of 1N4001 based on drocketman’s diagram. Put them in a heat shrink tube.
4. Solder one end with the blue wire.
5. Solder the other end in the hole connected to pin 6, where the blue wire was connected to.
6. Carefully place the diodes in the vacant space and make sure not to shortcut anything or interfere with the gears.
7. Close the case.

Thank you @drocketman for the ingenious solution!

Thanks so much for the follow up, your fix and the pictures. You are the first I know of to place the diode "fix" internally in an actuator. I am currently modifying a new factory actuator for @adavidw that he will install in his PacHy.
I will include pictures of the mod as you did.
It would be great if you would periodically report your continued experience with the mod. (if you notice any oscillation at all or any adverse operation)

 

[lacompas]

Not sure if this has been posted, but they released a TSB to update the HVAC software for this issue: https://static.nhtsa.gov/odi/tsbs/2025/MC-11019765-0001.pdf

 

[adavidw]

Not sure if this has been posted, but they released a TSB to update the HVAC software for this issue: https://static.nhtsa.gov/odi/tsbs/2025/MC-11019765-0001.pdf

Wait, what!?!?! That’s huge news, but at the same time not super helpful because it only applies to the 2022 for some reason.

The actuator is the same across years and the problem is the same across years so I could only speculate that maybe the software for that year is first to get fixed because they were working on some other related fix? Maybe it’s possible other years could get software fixes eventually (not holding my breath).

(This is TSB 08-193-25 for reference)

 

[SitKneelBend]

Wait, what!?!?! That’s huge news, but at the same time not super helpful because it only applies to the 2022 for some reason.

The actuator is the same across years and the problem is the same across years so I could only speculate that maybe the software for that year is first to get fixed because they were working on some other related fix? Maybe it’s possible other years could get software fixes eventually (not holding my breath).

(This is TSB 08-193-25 for reference)

Well I have a 2022 so I'll have it performed when the the airbag recall parts come out and let you all know.

 

[vicksterss]

Well I have a 2022 so I'll have it performed when the the airbag recall parts come out and let you all know.

Mine is a 2022. Cost was $500 plus. Around $20 for the part and more than $500 for labor. Dealership covered the cost because I heard it when I test-drove the (used) van and knew it didn't "belong". Hot dawg. Was i lucky! If I'd realized it a day later, I'd have had to pay.

And by the way, I told the (Toyota) dealership what it was b/c I found it on the Internet, with pictures. Took them a picture with the poster's comment. Thank gawd for the Internet and forums like this one!

 

[PacDave]

Thanks so much for the follow up, your fix and the pictures. You are the first I know of to place the diode "fix" internally in an actuator. I am currently modifying a new factory actuator for @adavidw that he will install in his PacHy.
I will include pictures of the mod as you did.
It would be great if you would periodically report your continued experience with the mod. (if you notice any oscillation at all or any adverse operation)

I just ordered a few 1N4371A 2.7v zener diodes. Each diode has a voltage drop of 2.7v which is equivalent to the voltage drop of 3-4 standard diodes when wired in series. Soon I hope to install a couple of these in my failed OEM unit that I removed awhile back. The replacement (I believe it is a Dorman) is already starting to show some beginning signs of oscillation. So I should know pretty quickly whether the zeners did the trick because the old unit was completely failed to oscillation every time I shut the van down.

 

[lacompas]

Wait, what!?!?! That’s huge news, but at the same time not super helpful because it only applies to the 2022 for some reason.

The actuator is the same across years and the problem is the same across years so I could only speculate that maybe the software for that year is first to get fixed because they were working on some other related fix? Maybe it’s possible other years could get software fixes eventually (not holding my breath).

(This is TSB 08-193-25 for reference)

I didn't search for other model years, so it's possible there are other TSB's for those. Timeline for the release seems to have been June 2025.

 

[adavidw]

I didn't search for other model years, so it's possible there are other TSB's for those. Timeline for the release seems to have been June 2025.

Yep, I did find 08-194-25 and 08-195-25 for 2023 and 2024 respectively, but nothing for older models.