1999 SOCH auto transmission problems

[lanxer57]

My transmission is slips sometimes going about 20 MPH, and produces the code P0733: gear 3 incorrect ratio. When this happens the engine RPM goes up a lot for no reason, and SES comes on a few seconds later. I tightened the input and output shaft nuts, and replaced the valve body with one that worked perfectly in a 2001 SOCH (even after I crashed it) a few months ago, and have driven it less than 25 miles scince then because it is not registered due to emissions issues. The transmission is leaking, but not from any of the panels I removed, and the fluid level is not low. A tiny bit high, if anything. It seems to be coming from somewhere around the bell-housing. It started leaking after I did the valve body and nuts.

Any ideas about what is causing it to slip, or the error code? Do (colorado) emissions tests even care about transmission related codes? Any ideas how to fix that slow leak because it is slightly annoying?
I do have the entire engine and transmission from the previously mentioned 2001, if the worst should happen.

[billr]

Some suggestions:

1) Disconnect the 10-pin cable on top of the trans and take it for a drive. With that cable disconnected you should get R,N, and one forward gear (3rd, I think) with no slippage. In fact, shifts should be very firm. If you don't get those results, then also disconnect the shift cable at the trans end and move the trans shift arm to the detented position desired (R or D). With the electrical cable disconnected you will have eliminated all electrical possible problems. If the trans doesn't give R and one forward gear with the 10-pin cable off, there is no point, right now, in considering bad switches/sensors/solenoids or low system voltage. With that electrical cable off, and the manual shift cable off, all problems external to the trans will be eliminated; the problem must be inside the trans case. Got it? If it works OK in that completely "manual" mode (cables off) then we go down one trouble-shooting path; otherwise we go in a much different direction. It is a very important and easy-to-do test!

2) If the trans does not behave OK with those cables off, then use a pressure gauge to do the "fuse pull" test of line pressure. This won't be a definitive test, poor results could be from several different problems, but would confirm the problem is something inside the trans case. Depending on what the (poor) results are, we could also get some clues.

3) Next step is to remove the VB and do air-checks of the clutches/servo.

4) The leakage you have noted is also a big clue, especially since it seems to have started after you worked on the trans. Even if you can't/won't do the air-checks, I would remove the VB and inspect all aspects of the VB install; gaskets and screws especially.

5) Unfortunately, I can think of no reason for there to be leakage into the bell-housing area that won't require removal of the trans for inspection/repair.

[lanxer57]

After removing the top plug, it immediately gave me an error code P0702, complaining about not having the electronic control from that plug. It also refused to go over 2300 RPM in D, 3 and 2 acted exactly the same. P worked normally, as did N. R was very responsive, and I feared that I had damaged the transmission when I tested that, it felt like the gears were jumping over each other, but it shows no sines of damage (other than it still leaking), and no metal flakes on the dipstick. It did not slip, and did not show the P0733 code. How would I control the car with the shift cable removed? I would expect it to be stuck in P.

[lanxer57]

After removing the top plug, it immediately gave me an error code P0702, complaining about not having the electronic control from that plug. It also refused to go over 2300 RPM in D, 3 and 2 acted exactly the same. P worked normally, as did N. R was very responsive, and I feared that I had damaged the transmission when I tested that, it felt like the gears were jumping over each other, but it shows no sines of damage (other than it still leaking), and no metal flakes on the dipstick. It did not slip, and did not show the P0733 code. How would I control the car with the shift cable removed? Get under the hood in the middle of the street?

[lanxer57]

I submitted that one twice...

Does it care if the plug is soaked in transmission fluid?

[lanxer57]

The leak appears to come from where the bell-housing meets the engine-block, starting at about the level of the oil-pan at both front and back of engine bay, and flows down both engine and transmission, coating the bottom. any idea how this problem could be solved? (so everyone can stop complaining about the spot on the driveway)

[billr]

As you describe it now, that leak seems like it could be from the engine valve-cover; not the trans at all. Those plastic VCs are prone to leaking. Generally, you can clean all surfaces below the VC/head gasket and then do frequent and careful visual inspect to see if that is where the leak is coming from.

Ignore any codes that pop up with the 10-pin cable disconnected.

I'm not sure about the 2300 rpm limit, that may be built into PCM software for when gross trans problems are detected. Maybe somebody else can advise, even go out and do a quickie test with there car.

D and all the other forward gears should behave the same with the 10-pin cable off. If it grabs R and D quickly, even harshly, and does not slip in either of those while driving, then you can probably ignore trying it with the shift cable also disconnected.

However, if you do want to try driving it with the shift cable off, then put it in D before you start out and simply plan a test route that won't require R. You will also have to jumper the P/N safety switch on the trans so you can start the engine in R or P.

Another common trick for easily and safely checking for trans slip is to hold the service brake on and slowly apply full throttle. A good trans should let the engine get up to the 1500-2500 rpm range and then "stall" it there, with the car at a stand-still. This builds up tremendous heat in the trans, since all engine power is being absorbed by the trans, so don't do if for long without letting the trans cool down. I only do it for 15-30 seconds max.

It is sounding like the basic trans innards are OK (no slippage), so we now do need to get into possible electrical problems. Check solenoid resistance (all should be about 5 ohms), check system voltage (should be 14-15V with engine running. Those are easy tests, let's get them out of the way. Use live-data to check the range switch and its adjustment, VSS, TFT, TSS, and much more!

Since shifts are harsh with the 10-pin disconnected, I think line-pressure is OK, but would still do the "fuse pull" test of that. That is also fairly easy and cheap to do.

I gotta ask... are you sure this trans has Dex3 fluid in it and not Dex6?

[lanxer57]

I do not know if this counts, but it is what they had, the bottle says "orieleys premium ATF" "for use where dexron-111 or mercon fluid is specified".

[lanxer57]

all solinoids test between 5 and 5.5 ohms

[lanxer57]

Why would oil be red coming out of the aluminum valve-cover? Why do I not see oil anywhere near the valve cover?

[lanxer57]

Holding the brake in D, it would not go past 2100 RPM. That seems exactly in the middle of your range.

[lanxer57]

I tried spraying the plug and pins with electrical contact cleaner, it did not help.

[billr]

If the leaking fluid is reddish, then forget about that VC bit; that is ATF and ominous, since it seems like there has to be a leak at the "front" of the trans, inside the bell-housing. Something like the convertor hub seal, pump housing seal, or *gasp* a crack in something. It is really hard to guess if that leak is just a nuisance or in a spot that affects control pressure enough to cause the problems you are having. Pulling the trans to check that area out is not a trivial job.

Solenoid resistances seem OK. Did you try the convertor stall in R, as well as D? Was the 10-pin connector off while stalling?

How about the live-data bit, are you ready to use that yet? It might help you avoid pulling the trans to check for the leak, or throwing a VB at it.

If live-data and the fuse-pull LP test and air-checks don't show anything conclusive, and the leak is found to be non-critical and system voltage is OK, then it is time to either throw a VB at it or get into complicated tests of the electrical drive to the solenoids. A new VB is probably most practical (and likely problem!).

[lanxer57]

I held the car still in D with the plug in the top of the trans, not in reverse, and not unplugged.

What fuse need be pulled? What line would be tested? Would a vacuum gauge work instead?

What stats in live data would be useful for this?

[lanxer57]

It does limit itself to 2100 RPM in reverse with cable plugged in, and brake held.

Freeze frame data when the code P0733 was first set was:
Fuel sys 1 / CL
Fuel sys 2 / N/A
Calc Load / 24.7%
ECT / 192 F
STFT B1 / 0.0%
LTFT B1 / 1.6%
MAP /10 inHg
Eng RPM / 1163
Veh Speed /23mph
TPS /3.1%
This is all that is shown in that freeze frame.

Live data idling in driveway in P now.
Fuel Sys 1 / CL
Fuel Sys 2 / N/A
Calc Load / 20.8%
ECT / 210 F
STFT B1 /1.6
LTFT B1 /-7.0
MAP /9 inHg
Eng RPM /740-750
Veh Speed / 0mph
Spark Adv / 18-20 degree
IAT / 102
TPS /0%
O2SLoc /O2S11
/O2S12
O2S B1 S1 /0.435V-0.759V
STFT B1S1 /3.1-5.5%
O2S B1 S2 /0.24-0.3
STFT B1S2 /99.2%
OBDSup /OBD11
This is all the data it shows.

What exactly is this "fuse pull" test?

[billr]

Oops, I forgot to reply to this one. Maybe I thought you were one of those posting along with "jacksdad" that you were getting new VB?

For the fuse-pull test, you need to get a 300 psig gauge with 1/8" NPT pipe port. Remove the trans fluid-temp (TFT) sensor, located beneath the spin-on trans filter, and connect the gauge there. You may need some extra adapter fitting, but they will all be easy-to-find standard 1/8" pipe. With the gauge installed, start the engine and read that gauge with the engine idling in P or N. Pressure should approximately 70 psig. Then, with the engine still idling, pull out the "LP" fuse and pressure should go up immediately to about 270 psig. Pulling the fuse forces LP (line-pressure) to maximum. These tests with the gauge will verify that the LP solenoid/valve in the VB can regulate LP, and that the pump, relief valve, etc. are capable of achieving full LP. Those pressure values above are ball-park guesses, post what you get if yours seem to be way off. I would do this test with the engine and trans warmed up.

For trans live data, you want to check these, at least:

Turbine Speed
Vehicle Speed
Gear Selected
Gear Commanded
Trans Fluid Temp
Torque Convertor Clutch (TCC) Slip
TCC Level Commanded
Line Pressure Commanded
Clutch Fill Time (for each gear)
Status of Adaptives Learn (for each gear)

You scanner may use different labels for the data, and may have more/less than what I show above. All those above, however were available with my OBD1 '95, so I would expect your '99 can offer as much or better if you have the right scanner. Tell us what you get and we can try to "decode".

Do you have compressed air readily available? An air-check of the clutches/servo is not hard to do (VB has to come off, though) and it would nice to have some confidence that the basic trans innards are probably OK.

[lanxer57]

On my cheap OBD2 reader, the only data that you listed there that is visible is vehicle speed. I will try to find one that displays the data listed. I will also try to find a gauge with a 1/8 in NPT, or use compatible adapters. I do have access to an air compressor, but will need to find a nozzle that will seal.

[fetchitfido]

I don't think I've seen those shown on any standard, consumer level, OBD-II reader. If you have a laptop there's a roughly $120 tool from VXDiag that fakes having a Tech-II which would give you the readings and potentially much more testing options.

[billr]

I think there is ELM327-type stuff that will get you full OBD2 data for a lot less than $120. More like $25. If nobody here can advise, I will direct you to a different forum.

[lanxer57]

With a very advanced obd2 reader, this was the data that was listed by billr, and some that sounded similar when idling in the driveway.
vehicle speed:0
RPM: about 750
turbine RPM: about 630
TCC slip RPM: about 110
throttle: 0%
current gear: P/N
line pressure: 60.9 PSI
torque: 0 FT/LBS
TCC status: OFF-OFF
PRNDL SW: PARK
shift mode: NORM
TRANS FLUID: 136 F
Clutch fill time and status of adaptives learned were not seen.