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Heyo i know this has been beat to death but i refuse to believe "its just broke" and would like to be able to properly diagnose it, if i need a new transmission so be it, but i want to understand the why
2008 Acura tl type s AT 144k miles
I acquired this car with a rough shift issue from 2nd to 3rd gear, when pulling codes i got the code P0777 Pressure control Solenoid B Stuck on, so i replaced transmission linear solenoids A and B, i tested B with a battery and it did not click so i believe it was bad, but the shifting issue remains and the code came back, i have a bi directional tester so i tested this and verified it is engaging and disengaging, however the code returned P0777, the previous owner did the 3x3 with mobil 1 full synthetic(i am in the process of switching it to honda OEM ATF as suggested in other places), and says he replaced the 3rd and 4th gear pressure sensors like everyone suggests, did i replace the correct piece? the dual linear solenoid, or is "pressure control solenoid" one of the 3rd or 4th gear pressure switches? is there any way i can verify these sensors the previous owner installed function correctly?
I am also getting an ECM/PCM relation failure, is there any known way to test if the PCM is causing this issue besides replacing it? i will be pulling the PCM tomorrow to check for corrosion or visible damage,
I know this is an old question but i couldnt quite find an exact match to my question elsewhere so figured id try again, i appreciate any and all the help!
I will get a new scan report and upload all the codes as soon as they re-appear
I doubt you'll need to replace your trans for a single rough shift.
Did you clear the codes after you replaced the A & B solenoids?
Did the PO replace the switches with OEM or did he get them off ebay/amazon (fakes?)
Do you have the luxury of pulling the switches and heading to the Acura/Honda parts counter to compare them?
Last edited by Pair of TLs; 01-21-2023 at 09:16 PM.
Reason: Capitol H
I dont see why not, i hadnt considered taking them to acura, i will try this on monday when they open back up, i messaged him and asked if they were original and havent gotten a response
I cleared the codes, reset the tcm/ecm through my scanner, and did the 30 second gas pedal thing all, issue persists unfortunately
does that code relate to the linear solenoid i replaced or to the pressure switches do you know? i cant find much about it online
I dont see why not, i hadnt considered taking them to acura, i will try this on monday when they open back up, i messaged him and asked if they were original and havent gotten a response
I cleared the codes, reset the tcm/ecm through my scanner, and did the 30 second gas pedal thing all, issue persists unfortunately
does that code relate to the linear solenoid i replaced or to the pressure switches do you know? i cant find much about it online
I've never had to replace the trans solenoids on ANY of my TLs, including a couple of 05s. But I sure got a shithouse full of codes when I replaced the switches with the bargain-priced fakes. I can't recall the exact code numbers, but replacing those with the Acura parts fixed the codes and the trans shifts perfectly ever since.
P.S. Compare the hole diameters of the switches at the parts counter. Even if the ARE the same size, I recommend getting them anyway.
Last edited by Pair of TLs; 01-21-2023 at 10:13 PM.
Reason: P.S.
Ill go pick a couple original ones up monday, he didnt seem like the fellow to buy OEM parts but i dont either if i have the choice, it appears i dont have the choice here lol, ill pick some up and update yall if it fixes it
PO just responded and said they were off rockauto, quick check reveals rock auto does not sell OEM pressure switches so that will be my next attempt, im seeing varying answers, some people say they have 2 switches, some people say the 07-08 added a 3rd switch, and i saw a couple that said "4th" but im not sure if they meant a 4th switch or the switch for 4th gear
PO just responded and said they were off rockauto, quick check reveals rock auto does not sell OEM pressure switches so that will be my next attempt, im seeing varying answers, some people say they have 2 switches, some people say the 07-08 added a 3rd switch, and i saw a couple that said "4th" but im not sure if they meant a 4th switch or the switch for 4th gear
The 07-08s have 3 switches. Two (#3 & #4) are easily accessible from the bottom via the wheel well and the other (#2) is on top under the battery/air duct area.
After looking at the rpm to speed chart above i have also realized that my car does not go into 5th gear, it runs at about 3k rpm at 65mph which is apparently 4th gear and it will not upshift from there, not sure if this is useful information
i COULD get it to go to 5th at a lower speed with the transmission in manual mode, the problem is when you drive long enough the d light flashes and disables manual gear selection
Yes zeta i understand the definition of the code, but i am unsure if “clutch pressure control solenoid” refers to the part i replaced or the pressure switch, i assume its the piece i replaced since it says solenoid but ive seen a few places saying the switches can CAUSE the code, not that the switches are referred to as solenoids
^
I don't see switches listed below:
As you already understand & as mentioned above about the switches, the only real way to find out IF they have cause / effect influence, in your case, is to cough up the 2 x 28600-RKE-004 (pressure switches) $68.70 X 2 1 x 28610-RKE-004 (pressure switches) $65.52 3 x 90471-PW7-A00 (crush washers) $3.01
for these OEM switches and test the short term results.
If you have a Honda dealer nearby or order them from a Honda online vendor, you can save a little $$ versus acquiring them from Acura.
Good Luck
True, the switches have their own code P0780-series. They wouldn't cause a P0777.
In 'colin's case, the solenoid B code, the valvoline fluid AND the shifting issues kinda throw a curve to the mix.
(I'm surprised there's no p0784 code for the 5th gear issue, but maybe because of the fluid?... )
Anyway, with the solenoid changed/tested and the code not clearing, I wonder if the battery needs to be disconnected again and perhaps driven and code cleared again?? Rinse/repeat? Or do you need to go thru the NAV and clear the DTCs?? Spitballing here. Why isn't the P0777 code clearing?
Yes to getting that Valvoline fluid out of there.
That may fix the hard shift and 5th gear issue by itself, since there's no switch codes??
Could the fluid affect the P0777 code to think the new solenoid isn't working?
Do that before replacing the switches.
Yes to getting that Valvoline fluid out of there.
That may fix the hard shift and 5th gear issue by itself, since there's no switch codes??
Could the fluid affect the P0777 code to think the new solenoid isn't working?
Do that before replacing the switches.
I’m using Valvoline ATF after I did a change with Honda’s ATF. It shifted better than with the Honda. I doubt it’s the fluid.
In reality getting more of the old fluid out the second change with Valvoline probably was the reason for better shifts, not brand of ATF.
my 2 cents. Shifts have degraded
a bit after 10kkm so I may have to replace my sensors tbh.
^ 2 x 28600-RKE-004 (pressure switches) $68.70 X 2 1 x 28610-RKE-004 (pressure switches) $65.52 3 x 90471-PW7-A00 (crush washers) $3.01
just stopped in at my local honda dealer and they said $370 for the set, about $125 each, so ill be ordering those online, also the code does clear, it just returns after 2 drive cycles (as the manual says its supposed to) i need to drive it today to get a proper code reading to maybe give you guys more insight, and im not sure what difference it makes, but it has mobil 1 full synthetic ATF and not valvoline at the moment, will keep yall posted!
sidenote: i somehow ran into the owner 3 owners ago while i was at honda trying to buy those switches, what are the odds? he told me they ran it quite low on fluid at some point but it was at least 50k miles ago so doubt its relevant
just stopped in at my local honda dealer and they said $370 for the set, about $125 each, so ill be ordering those online, also the code does clear, it just returns after 2 drive cycles (as the manual says its supposed to) i need to drive it today to get a proper code reading to maybe give you guys more insight, and im not sure what difference it makes, but it has mobil 1 full synthetic ATF and not valvoline at the moment, will keep yall posted!
sidenote: i somehow ran into the owner 3 owners ago while i was at honda trying to buy those switches, what are the odds? he told me they ran it quite low on fluid at some point but it was at least 50k miles ago so doubt its relevant
Have you tried going through the NAV screen to access the stored DTC codes and erase them?
I have not, i have cleared the stored DTCs with a scanner but not within the nav itself, i havent been driving it so currently it has no codes, im waiting on installing the pressure sensors to drive it again, on another note, does the 07-08 transmission have a filter? i can find online where it says 04-08 but i cant find a specific video showing the filter on 07-08 trans
I have not, i have cleared the stored DTCs with a scanner but not within the nav itself, i havent been driving it so currently it has no codes, im waiting on installing the pressure sensors to drive it again, on another note, does the 07-08 transmission have a filter? i can find online where it says 04-08 but i cant find a specific video showing the filter on 07-08 trans
The 07-08s DO have a filter, but it's inside the trans bellhousing, so nobody ever replaces it (unless you're pulling the trans.)
Originally Posted by 01collinp
How do you clear the codes through the nav?
From memory, key on, set up, more, acuralink, erase messages.
Attached photos of ECM, nothing stands out to say its bad but cant find many ways to test it online, will be reinstalling it and i will try to clear the codes through nav then drive until codes come back so i can provide exact codes Back of ECM Browning on pins Back of ECM(glare) Browning on pins Front of ECM
Description of the pressure switch test test results for switch A (2nd gear?) the test for switch B wouldnt run, it simply returned this message everytime i tried (i assume 3rd gear) test results for switch C (4th gear?/)
this is mostly a baseline for after i replace the pressure switches to see if theres any difference in the results, if anyone with known good switches can record live data please upload similar results for comparison! thank you!
Hey all. finally got all the parts in and it was nice enough to install everything, i installed 3 OEM pressure switches and have included pictures of the old and new of each one, the old ones have different letters stamped into the metal but other than that they look identical, color, material, hole opening, etc. My shifting issue persists, When i started the car up (after having battery removed for 2 days) I had the following codes:
Automatic Transmission-
P1745 - Shift Error M)
P1780 - Shift Control System (Transmission Default Mode)
P0746 - A/T Clutch Pressure Control Solenoid Valve A Stuck OFF
P0777 - A/T Clutch Pressure Control Solenoid Valve B Stuck ON
ABC/TCS/VSA
27-27 - Steering Angle Sensor DIAG Signal Erorr (initial) ---(the clockspring is out of the vehicle i believe thats why this one is happening)
61-1 - Modular-control unit initial IG low voltage
81-1 - Central processing unit internal circuit malfunction
83-19 - ECM/PCM relation failure
Does anyone know what else i can test or where the next step is from here? Also does anyone have a diagram of which shift pressure sensor correlates to which gear shift? i.e. if the one under the throttle body is the 2nd-3rd or if the one on the front behind the wheel well is 2nd-3rd? Thanks!
I have attached images for all data provided above, and a youtube video showing the shifting issue i am having, it is ONLY occurring from 2nd-3rd gear, it happens in manual or automatic, i cleared all codes from my scanner, and i reset the transmission via the 35 second gas pedal method and checked my trans fluid was in the lines.
Another thing i forgot to mention, the active test on shift solenoid B now works as its supposed to after replacing the switches
Well at least one code you dont really have to worry about is the 83-19 code. From my understanding that is basically just a code saying the ecu isnt seeing what it’s expecting to see. I had that code present when I had a bad wheel speed sensor but cleared when I replace the sensor. Honestly all of your VSA codes look like mine did when I had low battery voltage. My VSA and TC (the upside down triangle with the exclamation mark) lights seemingly randomly came on one day with those same codes. My battery wasn’t dead because it still started the car but it did slightly struggle more than normal. I charged the battery, cleared the codes, and they never came back.
The ECU may not have any visible issues but there have been cases where some of the solder joints were breaking down over time, were no longer making good connection, and causing problems. The fix was to just take a soldering iron and remelt the solder joints. I seriously doubt that’s your issue as I’ve never seen it happen on a TL. But some of the early 03-04 7th gen accords had that issue so it’s not completely out of the realm of possibility.
At this point if you’ve changed all these parts and nothing has changed with the shifts I’m just going to go out on a limb and say it’s more than likely something internal. I realize this isn’t a 4 speed but my 02 Accord V6 threw all kinds of solenoid codes and it ended up being a stuck piston in the valve body caused by trash from worn frictions. Obviously after replacing all the valve body components (I put the translab shift kit in it as well) and the frictions/steels the trans shifted better than new.
Hey Turbo, i appreciate your input, as seen above i had included pictures of my ECU so feel free to take a look and see if you can notice any soldering issues, i did not in person,
as for the valve body, it is my understanding that the valve solenoids are the valves, in which case on this transmission the valves are actually externally mounted and accessible without removal of the transmission, let me know if theres any type of test youd like to see or anything else you stumble across that may help me make progress on my issue!
It’s the same with the accord trans in that the solenoids are external but the valve body (where the pistons are) is internal. I had quite a few solenoid codes and tried replacing those first to no avail.
With the solder issue there are no visible signs. I guess maybe if you got it under a microscope maybe then? I don’t know, but to the naked eye it always looks fine. The other reason I don’t really think that is your problem is (besides the fact I’ve never seen it happen to a TL) that in every case I can remember the problems cause by poor solder joints would be intermittent. If this is a consistent issue that isn’t there one time gone the next then it’s extremely unlikely to be that. I only mentioned it as it is something you could try as a last ditch effort since some other Hondas of roughly the same type and vintage did have that issue.
Hey Turbo, i appreciate your input, as seen above i had included pictures of my ECU so feel free to take a look and see if you can notice any soldering issues, i did not in person,
as for the valve body, it is my understanding that the valve solenoids are the valves, in which case on this transmission the valves are actually externally mounted and accessible without removal of the transmission, let me know if theres any type of test youd like to see or anything else you stumble across that may help me make progress on my issue!
This is an illustrated parts breakdown of the valve body in the 08 type S auto to give you a visual reference for what pistons I’m referring to. Actually I think the actual nomenclature is CPC valve I’ve always called them pistons because that’s what the guy that thought me to rebuild transmissions called them and old habits die hard. Anyway they are the long cam looking pieces (sorry it’s the only way I could think of to describe them) that go in first followed by some seals and then held in by the #8 and #9 clips. The exterior solenoids determine which pistons get pressurized and when. But if the internal valve is seized in the valve body all the ecu sees is that the pressure isn’t correct where it’s supposed to be. So it in turn will default to that as a solenoid being stuck open or closed depending on where the piston is stuck at.
Obviously a bad solenoid is the culprit for this condition on an otherwise fully functioning transmission. But seeing as you have already replaced all of them the next logical step, in my opinion, is an issue in the valve body itself.
In that case i guess i will be running this car as long as it can before this causes the clutches to be destroyed, it is mostly to replace my truck for longer trips for gas anyways so hopefully it lasts a while! I appreciate everyones input and once it does completely die and i get it rebuilt i will post an update here about what the issue was internally, be it a CPC Valve or otherwise.
01-21-2023, 08:12 PM
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