09A GNZ transmission problem

[Charlie_M]

Anyone can help?

Sorry, I don't have any specific suggestions. But have you seen and followed the assembly instructions in the workshop manual here: http://foor.ee/m6/Mazda6/English/1738-1E-02D.pdf ? (Mazda, but same Jatco transmission). Look especially at the clearance specifications. Also, maybe check the reverse inhibit: supposed to inhibit low and reverse brake over 19 MPH, so no damage if R is selected accidently when moving forward.

[bjohns86]

Carfreak01,

What pressures are you seeing and at which ports? Reduction band or reverse clutch pressure taps? Are you seeing an increase in pressure as you increase the engine speed with your foot on the brake? It is likely not the reduction band if you are seeing all forward gears and no slipping here. If you only have no reverse I would look at the the low/reverse clutch and reverse clutch as these are ONLY used in "R". the manual linked at by Charlie_M is so-so, but it may have the proper reduction servo adjustment procedure inside as you said that you changed this in hopes it would help. It may now be out of "spec" and needs to corrected or you will have issues later due to either slipping or dragging of the band during operation. Tell me what pressures you saw and where and whether you see an increase and we'll go from there. If you need anything else such as the servo adjustment procedure, let me know.

Also, whenever one inspects the clutch material, even on a used transmission just about to be rebuilt, the builder wants to see the writing on the material as this shows minimal wear and glazing/burning and can even be used as verification for the new clutches. Don't hope to find the writing worn off as this is a bad sign, especially on a fresh rebuild. However, some clutches don't have writing on them at all, even when new, so don't jump to conclusions if it is missing. This all comes with experience so keep up your inquisitive nature and don't get bummed out by this bump in the road, you're almost in the clear! Good Luck!

Brad

[carfreak01]

Thank you for your reply.

I measured pressure at reverse clutch and at brake band actuator...for both reading was between 200 and 225psi at idle. When gauge was conected to reverse clutch (K2 on self study programme) gauge was at 0 when selector wasn't on R (as expected), whem selector is on R reading will go up to 225psi at idle.
I took a picture of the gauge while measuring pressure, click on any of the pictures of this thread and it will redirect you to my images on imageshack.com
The markings I was not expecting to see due to friction or at least worn were the ones on the friction material of the brake band, is not showing any signs of friction, either is not closing or is closing but low clutch is not moving thus not creatong friction when brake band is closing. Since it is not an electronic issue I think I will have to remove the tranny again, but I need to know where to look or what to look for.

Thank you for your help I really appreciate it.

[carfreak01]

Brad,

I don't have the servo adjustment procedures, if you can provide it will be very helpful.

While looing at the link Charlie-M provided I saw ATF going to brake band and to low clutch with the activation of the same valve but with different ports, I realized I haven't checked for atf pressure at low clutch, if it's possible to check it I will, don't know if there's a port to do so.

[carfreak01]

Hello.....the link provided by Charlie_M shows a servo adjustment procedure:
-tighten piston stem
-loosen stem 5 rotations.

Brad, is this the same procedure you have?
I will do this tonight and see what I find.

I did not checl for clearences when assembling, I will leave this for last since I have to remove the transmission for mw to do this.

Thank you

[bjohns86]

Send me an email at bmjohnson@huskers.unl.edu and I will send you the PDF. Haven't figured out how to post those here yet.

Brad

[driopel]

Send me an email at bmjohnson@huskers.unl.edu and I will send you the PDF. Haven't figured out how to post those here yet.

Brad

I hit some road debris and cracked the casing in multiple places. I took the tranny out, took it apart, Got the casing welded, put it back together with new seals. My problem now is that I have no reverse. Seems like a similiar problem to yours. I did not take any pressure measurements anywhere though and have no codes set. I did notice some grinding when I shifted from D to P, this happend twice. When I went to back out of the garage There was no reverse.

Did you find the problem for the reverse? How did you find it and what was the solution?

[elgtiloco]

if u still have issues, remove the valve body and behind it there are 2 O rings .....I bet u a case of whatever u like to drink that u forgot to put it on (u r missing one)

[carfreak01]

Hi Everybody,

I just want to continue with this until it is resolved, maybe the information I post here can be of help to someone else.
The last issue with the tranny was that it had high pressure on all gears, but it worked fine. I removed the VB to see if the issue was there but everything was OK, then assembled it back and tested for pressure and now it has no pressure on low clutch, I checked the reverse clutch and it has pressure and car pulls back with enough force, so the pump is working properly. I scanned the ECM and TCM but found NO codes. Then I unplugged the TCM to make it go into limp mode so 4th and R were available but still no pressure in the low clutch port. I removed the VB again checked every single valve and solenoid and harnesses but everything was OK, I assembled back and I still have no pressure in the low clutch port and high pressure in the low/reverse clutch port.
I can assume is not the pressure control valve or the N93 (line pressure) solenoid since there is pressure in R.
Car moves when in D but I have to accelerate like if it was slipping but gauge needle doesn't move so I'm assuming pressure is way too low.

The o-rings behind the VB are present, I made sure they were there and in good condition, I placed new ones when rebuilding the tranny.

I will keep looking into this and post later, if you have any advice I will appreciate if you share them.

Thank you,
Jose Luis

[carfreak01]

Update:

I scanned again the ECM and TCM before starting to perform any testing and found out that transmission was in limp mode, it showed all solenoid valves with short circuit either to ground or positive but it showed them as intermittent errors so I thought since the battery was unplugged when I plugged it back maybe the TCM detected a few errors and since they are intermittent then maybe those aren't really failures. I erased all codes and turn engine on, with pressure gauge plugged at low clutch port put it in drive and no signs of pressure, put the car in reverse and it pulled back strong.
Then I scanned again the ECM and TCM and found the same errors, all solenoids with short circuit to ground or positive.
It's odd that all solenoid valves are no good, I don't think that all the new solenoids are bad or that the entire harness is bad....maybe the TCM is no good?...and this is why it is in limp mode all the time?...I will have to look for another TCM and test it.

I also found 17748 error which is Camshaft Position Sensor G40/ Engine speed sensor G28 incorrect correlation, but I checked the three speed sensors and they are all OK, I don't know if this can trigger faults in the TCM.

Any thoughts????.....I need advice from the experts....CoolAirVW...Brad????

Thank you,
Jose Luis

[Charlie_M]

Update:

I scanned again the ECM and TCM before starting to perform any testing and found out that transmission was in limp mode, it showed all solenoid valves with short circuit either to ground or positive but it showed them as intermittent errors so I thought since the battery was unplugged when I plugged it back maybe the TCM detected a few errors and since they are intermittent then maybe those aren't really failures.

Are you using VCDS or a generic scanner? Can you post all the codes? It may be showing "intermittent" because the TCM will *not* keep trying if a short or open is detected. Once it detects an electrical problem, limp mode is triggered and you get only 4th and reverse (and that is mechanical, I believe, based on the linkage position only). In limp mode, all of the gear indicators are in 'reverse video', ie white letters on black backgrounds.

I erased all codes and turn engine on, with pressure gauge plugged at low clutch port put it in drive and no signs of pressure, put the car in reverse and it pulled back strong.
Then I scanned again the ECM and TCM and found the same errors, all solenoids with short circuit to ground or positive.
It's odd that all solenoid valves are no good, I don't think that all the new solenoids are bad or that the entire harness is bad....maybe the TCM is no good?...and this is why it is in limp mode all the time?...I will have to look for another TCM and test it.

Testing another TCM is a good idea, but you first should rule out harness problems and solenoid problems the old fashioned way ... with an ohm meter. And as CoolAirVW likes to point out , ohm testing is not conclusive unless they test bad. If you get all solenoid codes right away, chances are you will find something. Guidelines for ohm testing are in the FAQ, but post back if you have more questions about it.

I also found 17748 error which is Camshaft Position Sensor G40/ Engine speed sensor G28 incorrect correlation, but I checked the three speed sensors and they are all OK, I don't know if this can trigger faults in the TCM.

Any thoughts????.....I need advice from the experts....CoolAirVW...Brad????

Thank you,
Jose Luis

Jose, it seems to me that you have at least *three* separate problems going on that make it harder to diagnose.

1. Solenoid codes causing limp mode: this is always electrical AFAIK. Need to find the cause and fix it.
2. No forward (but was no reverse earlier, right?) Even in limp mode, you should be able to move forward in 4th. If you can't, and you don't see pressure in the right port, that tells me there may be a mechanical problem with the selector linkage to cause this.
3. Your 17748 code is engine related, not related to the tranny. G40 and G28 refer to the cam position sensor and the crank position sensor (60-2 tooth on the crank), both on the motor. The TCM does get an engine speed signal (which is how it finds unexpected slipping), but that sensor is in the tranny. That code in particular could be caused by several different things, and should be fixed, but would not cause your transmission issue.

Hope this helps. I haven't re-read your whole thread, but kudos for sticking it out and posting updates.

[carfreak01]

Hey Charlie_M thank you for your response.

I'm using VCDS, I don't have the codes at hand right now but I will get them later and post them.
The indicators on the dash are not in "reverse video" but transmission is acting as it was in limp mode. Car will move forward is in D but I have to accelerate it otherwise it will not move but even when starting to move forwards, gauge plugged at low clutch port will not show any pressure. If cars needs higher RPMs to move when in D then it might be because is in a higher gear, maybe 4th? but when in R it pulls back strong. Gauge when in R port it shows high pressure even at idle. Based on this two situations, I think TCM is in limp mode.
The no reverse issue I found at the beggining was that I left the manual valve unhooked and the piston for multidisc brake B2 (I think it was B2) unaligned, once I fixed those issues, R became available and forward gears were available and TCM was not showing error codes but pressure at low clutch port and R port was higher than it should be when at idle, so I dissasembled the VB to ensure that I had left everything correct but when I assembled it back and installed it back in the transmission I encountered this "no pressure at low clutch port", after that, I removed again the VB and checked valve by valve and all of them were assembled correctly, I also ohm checked all nine solenoids and they checked out OK, I also checked harnesses and they were OK, I put everything back together but still no pressure on low clutch port. This is when I checked for codes and found all solenoids with intermittent errors, I erased them and test again but no change, checked for codes again and found all nine solenoids again with intermittent errors.
I will try to ohm check the solenoids with them inside the tranny, maybe from the harness of the TCM if they check out OK I will look for another TCM and try that.

Thank you,
Jose Luis

[carfreak01]

Update:

I ohm-checked the solenoids but from the TCM end of the harness, so I will see what the TCM is seeing, this is what I found:

N88 --> 8ohms (Spec: 9-24ohms)
N89 --> 8ohms (Spec: 9-24ohms)
N92 --> 20ohms (Spec: 9-24ohms)
N90 --> 20ohms (Spec: 9-24ohms)
N282 --> 19ohms (Spec: 1-5ohms) NO GOOD
N281 --> 20ohms (Spec: 9-24ohms)
N283 --> 16ohms (Spec: 9-24ohms)
N91 --> 19ohms (Spec: 9-24ohms)
N93 --> 19ohms (Spec: 1-5ohms) NO GOOD
G182 Speed Sensor --> 556ohms (Spec: 400-600ohms)
G265 Speed Sensor --> 556ohms (Spec: 400-600ohms)
G68 Speed Sensor --> 569ohms (Spec: 400-600ohms)

I think that TCM is OK, I think that my next step should be to remove the transmission's oil pan (for the "n"th time) and unplug the solenoids and measure them individually, at least N282 and N93.
Also I will check the internal solenoid harness.

With G68 measuring correctly, I think the error code 17748 is due to camshaft position sensor, I will check G28.

Any input will be very much appreciated.

Jose Luis

[carfreak01]

Please disregard my previous post.

The readings I took from the TCM end of the harness I took them with the ground of the harness not the ground comming from the VB. Also, what I posted as specs for N282 and N283 are incorrect.
Check coolvdub's post for correct resistance of solenoids for 09A.
http://forums.vwvortex.com/showthrea...ation-Function

I removed all the solenoids and ohm checked them one by one and they all checked out OK. I removed from the transmission the solenoid harness and check it for continuity and it is OK too.

I also check continuity from the end where the solenoid harness plugs in and the TCM end of the harness and there is no interruption in any of the 10 pins (see pictures below).

None of the wirings show a significant resistance that could make the TCM look at a different value

TCM end of harness


End where the solenoid harness plugs into


Could it be the TCM is no longer good? I think that my next step is to find known good TCM and try it.

Any input will be very much appreciated.

Jose Luis

[carfreak01]

Update:

So after measuring and re-measuring, I found a slight difference between the old N93 and the new N93 solenoid.
When I measured N93 between tab (tab = tip where harness connects to) and ground, it gave me the expected resistance, but then I tried measuring between tab and the body of the solenoid and it gave me a reading I tried again and got nothing and then again and it gave me a reading.
Luckly I kept the old solenoids and check N93 and it gave me the expected reading between tab and ground terminal but it did not gave me any reading between tab and solenoid body.
Is this a case of short circuit? (see pictures below)

New N93, measuring between ground and tab.


New N93, measuring between tab and solenoid body.


Old N93, measuring between ground and tab.


Old N93, measuring between tab and solenoid body.


I really don't want to assemble again and find that TCM still shows error codes, by the way, I connected the solenoid harness again to all solenoids and TCM showed no error codes. But I think I have to turn the engine on and run selector through all gears so it can show codes in case it has failures, since oil pan is down I didn't do it. I want to make sure about this N93 issue first.

Any input will be very much appreciated.
Jose Luis

[CoolAirVw]

Since I normally recommend folks to NOT rebuild their own trans I normally dont post much to threads asking questions about internal rebuilding.

But I did notice you said, " have codes for all solenoids". This would normally mean the common wire or fuse that powers all the solenoids is broken (or unplugged?).

I love threads like these.

[Charlie_M]

But I did notice you said, " have codes for all solenoids". This would normally mean the common wire or fuse that powers all the solenoids is broken (or unplugged?).

Good point! And it falls in exactly with the OP saying (well, OK implying) he got different readings of solenoid resistance when checking via grounds on the harness versis via grounds on the valve body.

Jose, if you get different readings with different grounds, then you have a grouding problem.

And when checking the individual, lose, solenoid resistances, always go between the positive terminal and the grounding wire if present. If the wire is not there the solenoid body is used as the ground. The wire is used on a few solenoids that are rubber mounted, since the rubber insulate the body from ground.

[carfreak01]

Update:
I checked for continuity between TCM end of harness and connector where the solenoid harness plugs into and found no interruptions, I checked the solenoid harness for continuity and found no interruptions, I disconnected all 9 solenoids and left the ground terminal of the harness hooked to the VB and checked at the TCM end of the harness for short circuit to ground between ground and each one of the solenoid pins and everything is OK. I plugged all solenoids, poured ATF, scanned TCM, turned engine on and run selector through all gears but still no pressure at low clutch. Car behaves as if TCM was in limp but I scanned TCM again for codes but found nothing.
One odd thing I found is that with ignition on but engine off, Incan hear clicking noise inside the VB case if solenoids where randomly opening and closing really fast, this stops after a minute or so, when I heard this I scanned again the TCM but found no codes.

I checked all fuses and found only the lighter fuse to be blown, I replaced it but made no difference as expected, the only difference is that the lighter now works hehehe.

Also, before I installed the oil pan, with the solenoids plugged, I connected the battery and with ignition on I scanned the TCM and found no errors but when I was installing the oil pan I noticed the solenoids where hot, is this normal? Or this is an indicative that there actually IS a short to ground somewhere?

I am cluless now, after I hooked the manual valve of the VB and aligned the piston of the multi disc brake B2 transmission worked fine, the only issue was that it was showing higher pressure than it should be when at idle. This is when I removed the VB to check for correct assembly and after installing it back the problem with no pressure at low clutch started.
I will double check for short circuits and see what I find.

Any input will be very much appreciated.

Thank you,
Jose

[carfreak01]

Update:

I checked the solenoid's resistance from TCM harness again but now instead of having the new N93 I used the old N93 and now all readings are within the expected values when measuring from harness ground and from VB ground terminal. So far the electronics appear to be OK, and TCM seems to agree with that since there are no errors stored in it, and ECM is showing only the O2 sensors failure.

There's a fuse that is stained with some sort of oxyde, like if it was corroded, but it's for the fans. On the left side of the radiator, the wires are covered with dry coolant (white and purple kind of crust) it is an old leak that I have already fixed, I will dissasemble that section to see if I find anything.

I checked all leads at TCM connector and all three have 12V, (I already had looked at all the fuses but just wanted to make sure). Nothing seems to be out of place at wiring.

I'm going to remove for the Nth time the VB to check assembly again, not valve assembly but position on the case and maybe I will replace the solenoid harness since all plastic tabs are broken.

Any input and help on this issue will be very much appreciated.

Jose Luis

[carfreak01]

Update:

I checked for shorts to ground on the harnesses but found nothing. The only thing I found was a ground point with the nut loose and it was a little corroded, I think because of the bad connection it had. This was below the battery tray, I disconnected the 3 ground points that are there and cleaned them, tighten them but no changes on transmission behavior. Still no error codes so transmissionnis not in limp mode, but solenoids keep clicking for a few seconds after I have turned off the engine but kept the ignition switch on.
Since all these issues started when removing and putting back the VB I'm going to concentrate on that spot, everything else is OK, no shorts, no blown fuses, TCM gets voltage, no weird readings of solenoid resistance when taken from different ground points. I'm going to change the solenoid harness, I know is ok, it doesn't loose continuity when you move the wires and wires don't present more resistance to make the TCM look at a different value of solenoid resistance, but all tabs are broken.
I will continue with my search and post what I find.

Any help will be very much appreciated.

Jose

[carfreak01]

Update:

I'm still having the no pressure at low clutch port issue. The last thing I did is that I removed the valve body and check all valves again for correct assembly and they are correctly assembled. I checked the condition of the 2 round gaskets behind the VB on the transmission case and they are OK. I assemble the VB back using new lower and upper gaskets and I replaced the solenoid harness. Still no changes on transmission behavior. No codes stored in TCM or ECU but transmission still behaves as it was in limp mode. I performed the TCM reset but no changes.
Since transmission was functioning OK I assume is not an internal issue.
So now I'm assuming the TCM is no longer good, so in order to test this I used a really high tech device (see pictures below) which I plugged to the back of the TCM harness at the N88, N92 and N89 solenoid wires to see if it was sending voltage to the these solenoids.
These three solenoids are supposed to be activated when in 1st in auto mode.
With engine on, all sensors and modules connected, no error codes on TCM or ECU, gear selector in "D" and high tech device plugged to the back of the TCM, I got these readings:

N88 --> No resistance shown as if it was not connected but voltage was at 13V. With engine OFF
resistance is 18ohms.
N89 --> No resistance shown as if it was not connected but voltage was at 13V. With engine OFF
resistance is 18ohms.
N92 --> No voltage shown and 18ohms of resistance with engine ON and OFF

I should see voltage on these three wires, shouldn't I?

High Tech Device:


Closer look to high tech device connection


Any input will be very much appreciated.
Jose Walters

[carfreak01]

Hello all,
Update: I took the TCM to a TCM repair shop and they said it was not working, they quoted too high to repair it so I bought a used one. Installed it and clear all codes in all controllers. But made no change, I'm still having the "no pressure at low clutch and highest pressure in reverse clutch"
I moved the gear selector through all gears and check for codes again but found nothing. I'm still hearing the solenoids randomly clicking with the engine off but ignition on, does this means there's a short somewhere? if it does why are all fuses OK and no codes are showing?

I can discard an internal problem because transmission was working OK, this started when I removed the VB to check for slight high presure and then assembled it back. I have checked the VB more than twice after this issue and everything is in its place.

I really need some help with this. I have checked the TCM harness for short circuit but everything is OK, I think I will check all wire of the car in search of a short circuit.

Any help with this will be very much appreciated.

[carfreak01]

Update:
I checked the entire TCM harness and I didn´t find shortages....there are no shorts between wires of the TCM and there are no shorts between ground and wire leads of the TCM, readings at the TCM connector for all solenoids and sensors are correct.
I found the brake light switch in bad condition, it is a 4 pin switch but it´s stuck closed, it does´t matter if brake pedal is depressed or not, there is always continuity between terminals. This failure didn´t show up in the TCM, ECM or ABS modules, I changed the switch for a new one but transmission is still showing no pressure at low clutch.
I cleaned two ground points located in the plenum chamber but still no difference. I can still hear the solenoids opening and closing randomly with ignition on but engine off but now is slower.

One of the inputs for the TCM is sensor F189, which is the tiptronic switch, does anyone knows how to test if this is in good condition?....I can read a bit more than 500ohms between terminal 3 of multifuntion switch and ground but I see it is because is connected to F189 which it has resistors between ground and lead which makes this 500ohms but I really could´t tell if it´s correct.

Thanks in advance for any input you may provide.

[CoolAirVw]

One of the inputs for the TCM is sensor F189, which is the tiptronic switch, does anyone knows how to test if this is in good condition?....

You plug in vag-com and go to measuring blocks and look at the measuring block associated with the tip switch. You can see the switch change state as you move it to the tip position then you can see the individual switches change state as you move it to "+" or "-".

This cannot cause your problem though.

[carfreak01]

Thank you for your reply.

I was also thinking that F189 couldn't cause this "no pressure at low clutch" issue. I'm just curious to find out if that 500+ ohms reading between terminal 3 of F125 and ground is correct, this because if I unplug F189, there is no connection between ground and terminal 3 of F125, I know there are resistors in the circuit board of F189 and that can be causing the reading of 500+ ohms, since I don't have the schematics for that sensor I just want to make sure it is correct, brake light switch was not good but there were no DTCs stored for that, just making sure F189 is OK too.
I'm just making sure that everything that can make the TCM malfunction is in good condition.

Thank you,
José Luis

[CoolAirVw]

Have you considered that maybe your in the wrong tap when your testing for your pressure?

Or have you tried air checking the servo to see if the band will apply? (sorry I didn't re-read through the whole thread to see if you've done this)

One solenoid can stick and cause no reverse. I assume also, I think I remember reading, that you've replaced the solenoids. But maybe the valve that the solenoid acts on is stuck.

[carfreak01]

I have considered the wrong tap, but I made sure it was on the correct tap.

Transmission was working fine just with a slight high pressure, so I removed the VB to see if everything was correct, then installed it back and the "no pressure at low clutch" issue started.

Band does apply since reverse can be engaged and highest pressure is applied, and also if I increase RPMs when in D car will move forward but only at high RPMs, it behaves as it was in limp mode but TCM is not showing any errors and "PRND432" display is not showing differently (as when in limp mode) but if I on purpose disconnect something to make it go into limp mode, then TCM will show DTCs and "PRND432" display will light up differently.
This is why I assume there is nothing wrong internally with the transmission, I believe is electronic related.
I attached a wire to the back of the TCM connector to see if N88, N89 and N92 were being activated by the TCM and one of them was not, I took the TCM to a repair shop and they told me TCM was not working but quoted too high to repair it, I bought a used one but there's no change. The only change I notice is that with the old TCM (original) solenoids stopped clicking randomly when ignition was on and engine off, now with the "new" TCM random clicking is back again but after I cleaned two ground points and change the brake light switch these clickings are less and slower.
I don't want to ruin the TCM again.

Thank you for your help
Jose Luis

[carfreak01]

I forgot to tell you that yes, I did change the solenoids.
I change them all, but TCM detected a short circuit and new N93 was giving me a reading that old N93 wasn't, reading between lead and "O" terminal of the solenoid was OK on both solenoids, but when reading between lead and solenoid body new N93 was showing continuity but old N93 wasn't, I assumed that new N93 was no good and I reinstalled old N93....at the end I have 8 new solenoids and 1 old (N93).

Maybe old N93 is stuck and this is why I'm not seeing pressure at low clutch and it is why I don't see DTCs stored in TCM?
But then why N92 is not being activated by the TCM when D is selected?

[carfreak01]

Can anyone tell if 500+ ohms between terminal 3 of Multi-function switch wire harness terminal of 09A 5sp transmission and ground is correct? This is with the ingnition off. When I turn the ignition on (engine off) resistance between those two terminals drops to 57 ohms. I know there are many resistors that may be somehow connected, but I just don't know if that reading is correct. I cannot find anything on the manual that tells me if that is a reading I should be expecting.

I just finished checking all relays, fuses, ground points and I haven't find anything wrong.

Thank you all for any help you may provide.

[carfreak01]

Hello all,

I'm still having the "no pressure at low clutch port" issue. This issue started when I removed the valve body to see if I had left something wrong due to a slight high pressure and installed it back. Before this movement, transmission was working OK, all 5 gears kicked in when I test drove it after the rebuilt I performed to it, and after three corrections on assembly, reverse became available too.
The weird issues I found after the "no pressure at low clutch" started were:
-Solenoid N93 giving a reading between lead and solenoid body. I changed it for the old one.
-Brake light switch was always closed on both internal switches.
-Ground points dirty and one of them a little loose.

I corrected all these issues.

With TCM connected and engine running and no DTCs stored in TCM and ECM, I meassured N88, N89 and N92 which are the responsables for gear shifting and one of them was not recieving voltage. I took TCM to a repair shop and they said it needed repair, I bought a used one, installed it back, deleted al errors shown but still no changes in transmission behavior.
Today, with the recently bought TCM, I meassured again N88, N89 and N92 and they are receiving 13+ volts, I also checked N93 and it is receiving voltage, when in D, voltage is at 1+ volts and when in P with engine off, voltage is at 4+ volts, since is a modulation valve, I assume is correct.

So no DTCs, no limp mode activated (per TCM and "PRND432" display), resistance for solenoids, speed sensors and temperature sensor are all within their specified value (measured at T68a TCM connector), no shortages in all wire harnesses (engine bay, transmission, instrument panel) all fuses OK, all relays working properly and pressure gauge connected to the correct tab and still I cannot see pressure at low clutch.
I performed the electrical testing shown in the manual and all checked out OK.

I haven't performed basic settings to the recently bought TCM (used), could this make the transmission behave as it was in limp mode even when electronically is not?

I checked for voltage at F125 connector between terminal 3 and 6 and it is receiving 12+ volts, so my theory of having something wrong there went down the drain.

By the way, pressure gauge is working, I plugged it to the reverse clutch tab and it showed high pressure, very high as when in limp mode.

Any help on this will be very much appreciated

[carfreak01]

I just noticed something.....I unplugged the transmission harness (T20b) to make it go into limp mode and turned the engine on, I moved selector to R and car moved backwards, then I moved selector to D and car moved forwards but pressure gauge connected at low clutch tab didn't move, maybe because when in limp mode, 1st, 2nd and 3rd aren't available.

With transmission connected (not in limp mode) R is available and when in D car moves forward only at high RPMs, but with transmission unplugged (in limp mode) R is available and when in D car moves forward without having to accelerate. In both scenarios, pressure gauge at low clutch tab does not show pressure at all.
Transmission behaves as it is supposed to when in limp mode, but when not in limp mode, transmission acts as it was in limp mode but when in D car will not move.

When in limp mode, does ATF pressure by-passes N93 to apply to R and high clutch? if it does, then maybe my issue is that the old N93 is stuck, but if it doesn't then my issue is different.

thank you for any input you may provide.

[carfreak01]

So in order to see if N93 was stuck or not I unplugged the TCM and fed 12 volts between terminal 1 (GND) and terminal 66 (N93) and I could hear the solenoid click, so pressure control solenoid (N93) is in the specified value of resistance and it opens and closes, so that is not the culprit I believe.

I kept doing this for all nine solenoids and found out that some of them were not clicking when I fed 12 volts to them. I still have the old solenoids so I did the same with the old solenoids and obtained the exact same results.

N283 click
N282 No click
N281 No click
N93 Click
N92 No Click
N91 Click
N90 No Click
N89 No Click
N88 No Click

I dissasembled one solenoid that clicked and found there's a spring in it, and one of the solenoids that didn't click and didn't find anything that can make it click, so is it correct that 6 out of 9 solenoids didn't click?
I still think that my problem is electronic related, but I cannot find out what's wrong.

Any help you may provide will be very much appreciated.

[CoolAirVw]

If the pintle is in one position and you energize it, then it will click to the other position. If the solenoid is allready in the "clicked" position, then you wont hear a click. You almost cant do this check without pushing the pintle back mechanically or with hydraulic pressure or air pressure or something.

Have you verified you put the wires on the correct solenoids?

[CoolAirVw]

I just noticed something.....I unplugged the transmission harness (T20b) to make it go into limp mode and turned the engine on, I moved selector to R and car moved backwards, then I moved selector to D and car moved forwards but pressure gauge connected at low clutch tab didn't move, maybe because when in limp mode, 1st, 2nd and 3rd aren't available.

Is this just a comment? Of course if your in failsafe your not gonna have pressure at 1st, 2nd and 3rd. IIRC trans takes off in 4th on this trans when in failsafe.

With transmission connected (not in limp mode) R is available and when in D car moves forward only at high RPMs, but with transmission unplugged (in limp mode) R is available and when in D car moves forward without having to accelerate. In both scenarios, pressure gauge at low clutch tab does not show pressure at all. Transmission behaves as it is supposed to when in limp mode, but when not in limp mode, transmission acts as it was in limp mode but when in D car will not move.

This paragraph makes no sense to me. I thought your problem was no reverse?

When in limp mode, does ATF pressure by-passes N93 to apply to R and high clutch? if it does, then maybe my issue is that the old N93 is stuck, but if it doesn't then my issue is different.

There is no way to know this as oil schematics are not available for 09A Vw trans. You might look at the mazda stuff and maybe you could get an answer but VW and mazda VB are significantly different.

EDIT: I dont know why you said n93 there but n90 is the solenoid that inhibits reverse not n93.

[CoolAirVw]

also... have you attempted to drive forward? Meaning with the car assembled... not with the TCM disconnected or anything else? (sorry I dont have time to "re-read" to see if you did this.

You might gain some valuable peice of info if there was a missing gear or something.