Eurovan transmission struggles

[vazelinium]

Hello people.
I'm new to posting on this forum but professional reader.
Looking for suggestions because I'm running out of options.

Picture to draw attention:

So, one day 3 years ago out of nowhere while driving 40mph our favorite 01p decided to shift into parking. Of course planetary felt apart. My local transmission shop in Florida gladly agreed to rebuild it for very reasonable amount of money. After the rebuild everything was fine until speed sensor gave up. It affected shifting points but overall the van was drivable, transmission kept shifting and all. After a year of driving it like this I finally replaced the sensor. A few month after on a lovely morning I'm loosing the reverse, 10 miles later I lost all the gears. Called back to transmission shop and they rebuild it for the same little amount of money, but when they called me to notify that van is ready to be picked up they told me that they rebuilt all the mechanical part but there is electrical issue that prevents the transmission from shifting so they had their electrician check the wiring an he stated that TCM is bad and has to be replaced. So i picked up the van, took it back home and ordered Used TCM with the same part number.
TCM didn't help.
Here is picture of the transmission harness after "electrician" "Checked" the wiring:

I'm not goin to tell y'all that the shop sent me to F*ck myself since they do only mechanical work but not electrical and even with the 12month/12000miles warranty they not taking it back to repair properly.

I should describe the issue.
With tcm DISconnected, basically in limp mode operating manually, i have the reverse, 3rd and 1st.
with TCM connected i have reverse, 1st and second but it slips out of 3rd. Ill add the link with video.

Link




So what i have as for today.
1. Transmission harness repaired ant tested from TCM to all the components
2. TCM "repaired" by computer specialists. They said there was a hardware issue that was addressed
3. Most of the wiring between Instrument cluster, ECM and TCM tested
4. After cleaning of valve body I've got a few good shifts 1-2-3 but soon realized it is because of bad connection with pressure control solenoid (n93)
5. Rebuilt valve body installed to eliminate possible valve/solenoid issues
6. All 3 speed sensors are new

I might forgetting something.

Please if you have any thoughts share them with me.

[Stripped66]

[vazelinium]

[Stripped66]

Was it an actual 01P valve-body, or was it advertised as 01M/01P?
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[vazelinium]

[Stripped66]

[vazelinium]

[Stripped66]

Samba member bcollins (Brian) is located in Austin. He may be willing to test out your TCU.
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[vazelinium]

[Tvättbjörn]

Before you remove the valve body just check resistance of each solenoid on the main connector on the transmission according to the wiring diagram. That way you know that the wiring from the connector to the solenoids and the solenoid wiring itself is good.
However, it does not mean that the solenoid actually works.

I have also seen seen cracked / broken wires outside the transmission in areas where the loom moves a little bit. Rodent damage is a different possibility.

If you have a partial ( Lets say 10 out of 13 small wires in one wire ) broken / damaged wire it will most likely not set a DTC because the TCM still sees an ok signal / good circuit , but the solenoid might not get pulled because the wire is not large enough to carry the current anymore.

Wiggle the wires while performing your continuity wiring test. Especially the areas with movement in the engine compartment.

[Stripped66]

[Zeitgeist 13]

The fact that he trans threw itself into Park at speed strikes me as a hard wiring problem from the outset. That should've been investigated way back when it was first rebuilt--I know, not helpful now.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[vazelinium]

Thank y'all.

I've already mixmatched all the solenoids from 2 valve bodies so I'm assuming its not solenoid issue.

Zeitgeist 13 has a very good point and I understand that there is no magic and I already exploded the harness all the way from TCM to transmission 12 pin plug, checked the resistance of every wire that I was able to trace. Ribbon cable new, solenoids resistance within specs.

The only thing I can think of is that it was a short somewhere at the end of the harness where electrician been messing with and it burn da sh*t out of TCM, he left it the way it is and then when I plugged the new TCM I burned it also and computer repair guys wasn't able to find the issue.

It doesn't look to me like bad torque converter or any mechanical issues but i might be wrong since when I used to work in VW/Skoda dealer back in Russia I didn't gain much of experience with transmissions. And unfortunately I lost contact with the guy who was a transmission God at that shop .

Im probably gonna build the simple 7 bulb board to see the solenoid activations then we'll see.

[vazelinium]

Link



So, I built the board.
As I can see, it energizes n89(according to manual "energized in 2nd and 4th to apply b-2 brake") then after a second it goes of In the same time n92 stays on all the time during acceleration but it goes on and off. Also in 1-2 shift it applies n94 but according to the manual it only used in 2-3 and 3-4 shifts.

Im trying to figure out if this caused by faulty TCM itself or it could be wrong input data lets say from ECM such as speed or throttle position.

[Stripped66]

Does N93 ever go off?
It's a PWM circuit that should vary with engine load/rpm, and with the LEDs for N93 being constant-on, it suggests that it is bleeding off line pressure the entire time...

If N93 never goes off, either the circuit is grounded due to bad/damaged wiring, or the MOSFET within the TCU failed (circuit is closed).
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[vazelinium]