Resolved No 3rd and 4th gear automatic transmission

[Dryppical]

I have an issue where I have no 3rd and 4th. You can hear both of them click when on toggle switches but it only has 1/2. I’m at a complete loss right now. Both solenoids get power but won’t shift past 2nd. I don’t know what the issue is.

When TCU is unplugged it goes into limp mode so I have 3rd so none of this makes sense to me anymore. When I have the TCU plugged in and no toggle switches it doesn’t go in limp mode so it must not be detecting a problem. When I unplugged my power to my toggle switches and watched the lights when they get activated. 1st gear both are on and 2nd is one of them off, then it doesn’t go past that.

Any help is appreciated. I’m at the point where I just want to drop a match into the gas tank

 

[Dryppical]

New discovery. The tcu kicked it into limp mode. I guess it just needed more time to get angry

 

[FIBA M - EC17PSE]

When was the last time it was servcied or cleaned? Its possible its past due and needs a refresh/clean. Bit while you are there perhaps open the valve body and clean it all out check the balls have not damaged anything and leaking pressure, solenoids most likely are clogged with grit as they tend to go that way.

If this does not help then its possible the tcu is causing the issue which is not common issue but can happen randomly.

 

[Dryppical]

No clue when it was last cleaned I bought it 9 months ago and still haven’t been able to take it or a drive. I replaced all fluids and filters. Just doesn’t make sense why I have 1/2 and no 3rd when 3rd is just both off but when in limp mode I have 3rd. I’ll pull tcu codes later and see what that tells me

Also, I bypassed the tcu and still only have 1st and 2nd. No 3rd and 4th still. Maybe tomorrow I’ll drop the valve body again and see if it needs a cleaning. Don’t really want to drop it for the 3rd time

 

[o0GuitarKid0o]

https://www.dsmtuners.com/threads/lost-2nd-4th-f4a33-auto-kickdown-band.496544/

I went thru this myself a long time ago , I thought it was different gears at first .

if I remember correctly, With solenoid A,B


ON, ON = 1ST
OFF,ON = 2ND
OFF, OFF = 3RD
ON,OFF = 4TH

Limp mode is OFF ,OFF (3rd) so you can atleast "limp it home" .

check the kickdown band if you end up removing the pan again.

I can't remember how different the 2g is honestly , but you'll see I tried alot of things.
Figured I'd chime in

 

[evil_eagletalon]

Back probe the solenoids with a meter and long test leads see what the solenoids are doing voltage wise.

 

[Sirius1995]

Yea I think valve body has gone bad but do as previously said, here's a good flowchart to follow (specially for p0763) second solenoid valve, which is most likely the failing one, conditions are limp mode aka safe mode (stuck on 3rd)

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[Dryppical]

Before I dig into the transmission again. I decided to leave my toggle switches hooked up to see what gears were on. Both switches were on, so I had first then when it shifted both turned off so I had 3rd. Turns out I have 1st and 3rd.

Now when I was using the toggle switches, I had both on for first and that worked good. Switched A off and it shifted which I presumed was 2nd. Then when I flip B off it doesn’t do anything which would be 3rd. So today I put on my thinking cap and since it only functions with both on and both off, I’m thinking maybe the solenoid wires are touching somewhere, so if one gets power, the other gets power and it’s not supposed to do that. I’ll go and get some voltage readings a little later today and I’ll update you guys with my findings

Also, if I would try to shift into what 4th would be, I would be back in first, my hypothesis makes sense to me so I’ll chase that for starters

 

[evil_eagletalon]

Before I dig into the transmission again. I decided to leave my toggle switches hooked up to see what gears were on. Both switches were on, so I had first then when it shifted both turned off so I had 3rd. Turns out I have 1st and 3rd.

Now when I was using the toggle switches, I had both on for first and that worked good. Switched A off and it shifted which I presumed was 2nd. Then when I flip B off it doesn’t do anything which would be 3rd. So today I put on my thinking cap and since it only functions with both on and both off, I’m thinking maybe the solenoid wires are touching somewhere, so if one gets power, the other gets power and it’s not supposed to do that. I’ll go and get some voltage readings a little later today and I’ll update you guys with my findings

Also, if I would try to shift into what 4th would be, I would be back in first, my hypothesis makes sense to me so I’ll chase that for starters

Makes sense i would pull the valve body apart and make sure all the valves are moving freely in there bores. Also you can check resistance from outside trans to actual solenoid to make sure its not shorted and has acceptable resistance in the wire.

 

[Dryppical]

I was able to pull codes and got 84 which is an open/short for solenoid b. Where should I start? I read another forum about it being the tps needed adjusted so I did that and no change

 

[Dryppical]

I got 21.9 ohms on A solenoid and 23.1 on B solenoid

 

[evil_eagletalon]

Measure resistance from toggle to trans solenoid connector. Also ensure there is no resistance in those wires to ground.

 

[o0GuitarKid0o]

I was able to pull codes and got 84 which is an open/short for solenoid b. Where should I start? I read another forum about it being the tps needed adjusted so I did that and no change

Thus brought back some painful memories .. https://www.dsmtuners.com/threads/tcu-capacitor-failure-urgent.510073/#post-153635935

I had a simular error code when my tcu took a crap on me.
I'm curious how your toggling the solenoids?

Hard wired into the connector? No tcu installed?

Lots of good information on toggling solenoids in that post, I have some spares I'll try and find and ohm out

 

[Sirius1995]

I was able to pull codes and got 84 which is an open/short for solenoid b. Where should I start? I read another forum about it being the tps needed adjusted so I did that and no change

As I told earlier, that's probably what it is as it's really common, you can try replacing valve body but it always is mis or hit with aftermarket so my suggestion is to either buy a used working tranny or find OEM known good valve body

 

[Dryppical]

So I checked the solenoids wires from the connector to tcu connector and the B solenoid was getting grounded out somewhere so I snipped the wire and ran a new one. Now it’s no longer grounding out. Still same issue. Next I will test my toggle switches and see if I can at least manually shift with them to rule out if tcu is actually good or bad. I’ll upload a picture of my toggle switch setup later. I have it wired to the solenoid wires and tcu unplugged. A “new” valve body will be my last step. Would be cool if my problem wasn’t that but we will find out soon enough

 

[CrackedDSM]

You're not trying to use the switches with the TCU plugged in are you?

 

[Dryppical]

I am not, it is unplugged

 

[evil_eagletalon]

May be even a plugged up solenoid screen. If your gonna remove the valve body might as well do a shift kit while your in there.

 

[Dryppical]

I suppose I’ll drop the pan for the 3rd time and give the solenoids and valve body a good cleaning and see if that fixes it. If that doesn’t then new valve body? Is that the options I’m left with?

 

[evil_eagletalon]

I suppose I’ll drop the pan for the 3rd time and give the solenoids and valve body a good cleaning and see if that fixes it. If that doesn’t then new valve body? Is that the options I’m left with?

The valve body is as mechanical as it gets. If your gonna remove it and take it apart to clean it might as well install a shift kit. The only thing that can really go bad on a valve body is the seperator plate in between the body halves. Follow ipts video to the t and youll be alright. Another tip i wish i had when i did the job would to put a gopro on your head to be able to go back if you get lost on re assembly.

 

[Sirius1995]

I suppose I’ll drop the pan for the 3rd time and give the solenoids and valve body a good cleaning and see if that fixes it. If that doesn’t then new valve body? Is that the options I’m left with?

I'm not sure if you're reading my replies but I've been advising you from the start

 

[o0GuitarKid0o]

I suppose I’ll drop the pan for the 3rd time and give the solenoids and valve body a good cleaning and see if that fixes it. If that doesn’t then new valve body? Is that the options I’m left with?

Inspect the kickdown band while you have it off , you'll see if it's cracked or not ,shouldn't be any play if I remember correctly

 

[1990TSIAWDTALON]

You can still get replacement solenoids if needed. I have a spare set somewhere (Because I have 2 of EVERYTHING). Something to ponder. ALSO, if you need a NEW separator plate, JNZ has them. I just got one last month.
I just now noticed you have a 2g so I am not sure if the separator plate is the same so double check me on that part number!
Marty

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[CrackedDSM]

The fact you have 3rd when the TCU is plugged in is throwing me for a loop, and makes me wonder if somehow the toggle switch wiring is incomplete somehow. Too bad you don't have a power probe, or I'd say put power to each solenoid wire at the actual transmission plug on the top of the trans, and see if it still only has 1st and 2nd. If you have someone GENTLY brake torque it while you do it, you'll feel the transmission shift(or not shift).

I 100% think it's a wiring problem somewhere. Or something stupid.

 

[Dryppical]

I'm not sure if you're reading my replies but I've been advising you from the start

I have been reading your replies. I just really don’t want to drop the pan again. Trying to do everything before dropping the pan again.

The fact you have 3rd when the TCU is plugged in is throwing me for a loop, and makes me wonder if somehow the toggle switch wiring is incomplete somehow. Too bad you don't have a power probe, or I'd say put power to each solenoid wire at the actual transmission plug on the top of the trans, and see if it still only has 1st and 2nd. If you have someone GENTLY brake torque it while you do it, you'll feel the transmission shift(or not shift).

I 100% think it's a wiring problem somewhere. Or something stupid.

I wouldn’t doubt it’s the wiring. The previous owner did a lot of questionable things like cut the starter relay and fuel pump relay out. Couldn’t tell you why. Snipped wires everywhere. It’s been a mess. A power probe would be very useful right now. I just thought of this. I have an extra harness that I can snip the solenoid plug off and just run my wires straight from the plug to my toggle switches. I’ll upload some pictures here in a little bit