A-110(a): DIY Guide to replacing 3rd & 4th gear pressure switch for 3G TL (2004-2006)
 

Since there is no formal guide other than the one in the service manual, I decided to document the replacement of my 3rd and 4th gear pressure switches.

For the record, my transmission has about 35,xxx miles at the time and I am the first owner. The shift quality is decent, I haven't noticed anything unusual other than 3rd gear holding on steep inclines under load. I just recently did a 1x1 drain/refill of the transmission fluid at an Acura dealer as well (about 1K miles ago prior).

Materials needed:
x1 3rd Gear Pressure Switch (28600-P7Z-003)
x1 4th Gear Pressure Switch (28600-P7W-003)
x2 sealing gasket (90471-PW7-A00)
x1 brake cleaner (to wash away residual AT fluid)

Tools required:
10mm wrench
22mm wrench
flathead screwdriver
lift (or jackstands)


On to the pictures.

Attachment 54646

Attachment 54647

I brought my car to my friend's shop (where he did the Accord foglight install). the car was raised and immediately, you will have access to one of the switches. You first undo the two 10mm bolts that hold a shroud, and then unplug the two connectors just so that you can swing the shroud out of the way:

Attachment 54648

to see which bolts im talking about, see this pic from e30cabrio:

Attachment 54649

that open hole in the middle of the pic is for one of the bolts. the TL has two holding that shroud.

the other switch is visible once you remove part of the splash cover along the inner fenderwall. this is what you should see:

Attachment 54650


You will need a 22mm wrench to unscrew each switch from their location. once you got them loose, unscrew by hand. unplug the connectors as you go and reconnect them once you put everything back. I suggest doing one sensor at a time.

Attachment 54651

Now for the details.

I noticed that the transmission housing has moulds on it that actually tell you which is which. Now, those who may know which switch is which may have no problem, but in the event you forgot (like me), one way to determine which goes where is by looking for these indicators, see below:

Attachment 54652

The amount of fluid that drips out is not much, but to get a sense what to expect, I took a shot:

Attachment 54653

You will need to use the brake cleaner to remove the residue of the AT fluid on the parts of the suspension. depending on how much got out and where, you can just spray liberally:

Attachment 54654


Finally a pic of the switches I replaced. 3rd gear on the left, 4th gear on the right.

Attachment 54655



Driving Impressions

Immediately after having these put in, I did notice an improvement of the car's shifting habits. I can't really quantify it much, but the shift from 2nd to 3rd and 3rd to 4th now happen much quicker. Put it in another way, they arent as "sloppy" as before. Even after applying load and a couple of WOTs, they are just noticeably different. Frankly it feels like Im driving a brand new car.

I would definitely recommend this as a Preventive Maintenance item. I likely will do it in around 70K miles just to keep the 35K mile mark I set. for the low cost and ease (even though I personally didnt do it), I think it is a worthwhile investment, along with doing the drain/refill procedure for the 3G TL AT transmission.


thanks to I hate cars for starting the transmission thread and credit goes to those that provided the part numbers as well as e30cabrio for one of his reference pics.

Wow! What an awesome right-up! Thanks for creating the DIY :thumbsup:

:agree: It's been added to the 3G garage A-110!

awesome write-up!

I'm ignorant... what does this do?

Awesome write up!!!!!!!!!!

+1 Matt is a hero indeed :thumbsup:

It is more of a preventive measure for those with the AT transmission on the 3G TL.

I hate cars had started a thread that brought about looking into doing this to prevent transmission failures for owners.

the thread is here:

https://acurazine.com/forums/3g-tl-2004-2008-93/very-interesting-conversation-my-transmission-builder-tl-721508/

see posts #1, #46, #139. those pretty much tell you all you need to know. personally I felt an improvement and, despite being under warranty, I just wouldn't want to break my OEM transmission and end up getting a reman. I plan to do this as part of my regular maintenance as it doesnt do any harm, and very easily does more good.

Does anyone know anywhere in norcal I can have this done? I have the parts already...just need a place/mechanic.

you can try a local dealer if you have to. otherwise, any regular mechanic should be able to follow the instructions quite easily.

Hey bud.. nice write up... but,

Those are the wrong P/N's.. Those go to 2G TL's the 1G MDX ('01-'02) and 1 & 2G CL..

I'm not sure on the specs of those pressure switches but the rating for the 3rd Gear should 33psi and the 4th gear is 27psi.. I believe the colors are black/ grey & beige.

The correct P/N for the 3G TL should be:

04-06 TL (Texas Instruments, TI)also compatible with
05-08 RL
07-09+ RDX
03-09+ MDX

07-08 TL (Washimiya?)Edit: Don't panic.. just because those pressure sensors / switches go to the gen of crap transmissions doesn't mean they aren't good, the transmission design itself was poor.. but the specs may be different.. I'd change them out and flea bay those if you can't return them.

that's odd. I went to three different local dealers and looked them up personally and these are the correct P/Ns. i had them print the sheets out to confirm we were looking at the same thing.

Okay I verified that the pressure spec is the same but the body of the switches and possible reliability spec is different. The switches you have are described as stepped body whereas the matching P/N's have a flat body. Did you notice a difference between the new & old switches physically or to the harness connection?

nope, they are identical as far as i can remember. i watched the entire time and the plugs and connectors/harnesses fit fine. im pretty anal when it comes to my car and i went to three dealers to confirm the part numbers (as the transmission thread showed two different part numbers, those with the -RAY- in the middle and those with the P7W/Z in the middle). i specifically asked the three different parts people and had them print out from their screen the part in question.

after i was satisfied, then that's when i proceeded. so the part numbers you pointed out and the ones I got are technically (for all sakes and purposes) work the same and work on the 3G TL.


the entire process (including me interrupting for pics) took no more than 15 mins. nothing fancy was done nor any special fitting. it was all plug and play.

This should be the physical verification:

They look the same except for the flush connection.. could be a redesign for several reasons including thermal / reliability, although the actual spec is the same.
http://farm4.static.flickr.com/3641/...1ce28590_o.jpg

that's very good information. since the spec is the same, personally I dont think it matters at this point. we checked to make sure the connections were secure and that nothing didn't seat right.

plus, as I've said, I had peace of mind confirming from the (three different) parts department that the switches were indeed compatible. I gave them the part numbers you specified and they were ok.

but thanks for the clarification :thumbsup:

Whoa.. I started digging a little more to find out why 07/08 had a different P/N.. come to find out there are two 3rd clutch pressure switches for that bad boy.. it was redesigned.. wow..

07-08 TL

#13 (2) & #14
http://www.acuraoemparts.com/delray/...p8_atm0710.gif

04-06 TL

#12 (1) & #13 (1)

http://www.acuraoemparts.com/delray/...p4_atm0710.gif

edit:

learn something new everyday...

wow thanks! at least we have all this useful information in one place. much easier for those not as fully mechanically inclined like me :D

Yeah.. it seems the adding of an addition pressure switch to the 3rd clutch just reinforces Matt & his transmission guys theory.. that the switches failing will cause premature transmission failure or at least reinforces the importance of their functionality.. I wonder how different the clutch specs are between the two sets and which year clutch Matt looked at.. hmm..

we should start calling them 3G & 3.5G.. jeezz.. I'm gonna trade for an 07.. :rolleyes:

I know. Im going to PM a mod to change the title to include (2004-2006 3G TL only)

thanks for the additional info!

very nice wright up, I might give this a go over the weekend.
This helps as-well for shift speeds https://acurazine.com/forums/3g-tl-performance-parts-modifications-112/transmission-solenoids-adjustment-728370/

Great Write-up.

Done. Too long for the "only" but I got the year in.

Nice catch majofo.

Looks pretty much like the same procedure for the '07/'08 just different part numbers and the one additional 3rd gear pressure switch, right?

thanks again for the edit! :thumbsup:

the procedure seems pretty much the same in a way. and yes, it's an additional 3rd gear pressure sensor/switch for the 07-08 cars. :)

Subscribed!

Isn't the 07/08 a different transmission. Like the one from the RL? And if so, is this maintenance really needed? I haven't heard much of trans failures from those guys? I figgure there's a reason why they changed the transmission on those years...

oh, and AWESOME write-up. I tackled those switches on my 04 a few weeks ago with my 105k service. I can't say I noticed any difference, but for the $$, I don't mind the peace-of-mind if the theory holds true. It made sense to me.

the 07-08s have an extra 3rd gear sensor/switch to replace, as noted by Majofo above. I believe I read somewhere that they use a tranny similar to/or based on the RL tranny.

for preventive maintenance, these switches are worth it imo. i for one have noticed an improvement within the first few minutes of driving.

Nice pictures!!! Its also possible to do this without getting the car on a lift (which my car can't get on :tomato: )

I was too slow to pictures, but thorough!! Good job :thumbsup:

you can jack up the driver side, put it on a jackstand and remove the driver side front wheel. its just easier to do this on a lift as you can reach behind the tire and replace the sensors that way.

added some scans from the service manual:

3rd gear switch:

Attachment 54579


4th gear switch:

Attachment 54580

sick write up!! That took a lot time and knowledge, thanks for the great DIY

anyone done it on jacks yet? how much harder was it on just jacking up the driver side? gonna do this later today.

i think it shouldnt be that bad. I personally would remove the driver side front wheel to give you more room. the switches are literally on the other side of the splash cover.

thanks. going to do this later. i'll add more pics with the wheel taken off and the car on jacks.

Well I just did both sensors and a 3x3 fluid drain. All I can say is the difference is night and day... The occasional vibration I was getting while shifting has not occured since but a few days will tell the full story there, thanks for the awesome writeup.

mk

that's good news! keep us updated :thumbsup:

i was planning to change the tranny fluid and pressure switches at 30k miles as some PM... if a writeup for the 07+ isn't up by then, ill take pics of the addt'l switch to add into a writeup...

Quick question... how fragile are the sensors? My 2 year old daughter got a hold of them and dropped them from counter height onto a tile floor. They seem ok but not sure if there are fragile internals that might be broken.

Jung

They are usually packaged to withstand great mechanical stress. I wouldn't worry at all. The components within should be very durable.

Did my 04 with 88K this evening. Definite improvement in both up shifts and down shifts. Just bought the car a couple of weeks ago and wasn't satisfied with the shifting. Came back to this forum, had CLs previously, to find a solution. Thanks to all.

Used jacks and didn't remove the wheel. Should have removed the wheel. You have to be pretty ambidextrous to accomplish the task in that tight of space.

Be aware that the wire connectors have a release tab on the end where the wire exits. Just press the tab & pull the connector off of the sensor.

This is a lot more than "Preventive Maintenance". In my case, its better than a remanufactured transmission.

Now I can really enjoy my TL.

Thanks for posting. I did this last night... very, very easy thanks to your pics. I ended up just jacking up the corner and removing the tire.

After I changed the switches, I took a test drive and immediately noticed a difference -- much more clean shifts. I can confirm too on my 1hr commute this morning (in traffic and on hills) that the shifting is much, much better. Cheers to whoever figured this one out.