trans pan drop/drain/fill - now problems

[RiverWolf]

The patient in question is a 2003 4Runner V-8 4x4. Due to a stripped drain plug in the trans pan (spinning in hole, not backing out), I installed a new trans pan this weekend.

Now the fun begins. Engine was started when the trans was probably still a good bit low on ATF (added more than called for in a drain&fill, but apparently not enough more) and immediately threw a check engine light...also activated the VSC/TRAC Off lights, but that's probably a 4Runner specific thing. Now that the fluid is fully topped off, the lights are still there. This is a 5 speed auto, but she won't shift into 5th or lockup the torque converter in 4th. Also getting a *hard* 2->1 downshift when slowing down from speed. Otherwise behavior seems normal...no delay on P-R-N-D selection/engagement (N-D does have a bit of a jolt) and upshifts from 1->4.

Checking the DTC list in the FSM, there are a couple of conditions that can lock out 5th. I'm hoping it's as simple as the ATF temp sensor reading open on the initial start due to low fluid and the computer won't let me out of "limp" mode until the code is cleared. The other possible codes relate to various AT solenoids, which doesn't seem to be a likely scenario based on my layman's understanding...there should have been enough fluid in the pan to cover the valve bodies on the initial start.

The plan is to stop by AA/AZ on the way home and get the codes read and reset. Could I be lucky enough that it was just the temp sensor reading open? Any other thoughts?

TIA.

-Brent

 

[hate2work]

You'll find out more when you get the codes read. Not sure if this applies in your case, but I've seen others who simply disconnect the battery for 30 minutes or so to reset the onboard computer.

How did you manage to add more than called for in a drain and refill, but still be low on fluid? Maybe if you drop the pan like you did it takes more to refill?

 

[NEOhio_Bob]

It does sound like the transmission computer has gone into limp mode, and probably won't reset until the codes are cleared. Often, the manufacturer specific codes (which include most of the transmission codes) aren't read by the generic low cost code readers, so Autozone may or may not be able to give you the actual codes. Also, the last time I had them read a vehicle, they said they had a policy that they would not clear codes...strange.

I think the suggestion to disconnect the battery for a while is a good one...there's a good chance everything will go back to normal and you won't need to give this a second thought.

 

[milwaukee]

Toyota's horrible diagnostic design disables trac control and vehicle stability anytime a code is triggered.

If it were me I would be [censored] sure the fluid level is correct and clear the code and see what happens. My guess is you have refilled incorrectly.

Are you certain the correct fluid was used?

 

[RiverWolf]

Originally Posted By: hate2work

You'll find out more when you get the codes read. Not sure if this applies in your case, but I've seen others who simply disconnect the battery for 30 minutes or so to reset the onboard computer.

How did you manage to add more than called for in a drain and refill, but still be low on fluid? Maybe if you drop the pan like you did it takes more to refill?


Yes, the pan still holds fluid that won't come out via the drain plug. I also ended up letting it drain something over 12 hours due to finding out I needed a deep well socket to drop the exhaust crossover pipe below the pan after the stores had closed Friday night. Due to the crossover pipe, the pan was left loosely attached to the trans, but drippage had all but stopped before I called it a night. However, next morning I found evidence of additional ATF drainage...apparently the trans/torque converter decided to burp some more fluid during the night as everything cooled down.

So, long story longer (and with more embarrassment), a standard drain&fill via the plug calls for 3.2 quarts. I started with 4 quarts on the refill, figuring it might still be low, but should be in a safe range for starting. Immediately triggered the CEL. After backing off the ramps and pulling back into the garage...an R-N-D engagement...checking the fluid showed it still below the "cold" range, which isn't even a valid diagnostic in the FSM. Poured another quart of Toyota T-IV in and got somewhere between the Cold and Low Hot mark on what was essentially a cold trans so figured I should really be in the right neighborhood when at normal temp. Drove it down the street around the cul-de-sac and back about 25-30mph tops, upshifted 1-2-3 no problem, but went bang on the 2->1 down. Out of ATF so had to wait until this morning for dealer to open (drove wife's car to dealer). Ended up adding another quart+ for a total of smidge over 6 quarts added back. Looked good on the dipstick hot range after a couple trips up and down the street and only read a bit above the full mark after the 11-12 mile drive into the office with 4th and no torque converter lockup.

Thanks again.

-Brent

 

[demarpaint]

AAP in NY won't clear codes. I'd suggest disconnecting the negative battery terminal of about 30 minutes. Leave the door open until you're ready to reconnect the battery. Hopefully it is just a matter of clearing codes, and the battery disconnect accomplishes that for you. Good luck!

 

[RiverWolf]

Originally Posted By: milwaukee
Toyota's horrible diagnostic design disables trac control and vehicle stability anytime a code is triggered.

If it were me I would be [censored] sure the fluid level is correct and clear the code and see what happens. My guess is you have refilled incorrectly.

Are you certain the correct fluid was used?


Yep, a little over 6 quarts of T-IV were added.

The most disconcerting thing is none of the 4Runner FSM suggestions for DTC-07xx codes actually suggest checking the fluid level. Either Toyota doesn't think low fluid will trigger a code, or it's assumed a technician would start with the fluid before proceeding to the sensor/ECM diagnostic.

-Brent

 

[bepperb]

I'd try disconnecting the battery for half an hour. On Highlanders there if a fuse you can pull to do the same, not sure about the 4runner. But yes, one bad code and everything else will disable (vsc, overdrive) for "limp home" mode until the code is cleared.

Get it cleared and you'll likely be out of the woods, but at the very least we can help you more by knowing what they are.

 

[RiverWolf]

No joy.

Code is P0778. In Toyota speak, Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2). Looks like it's mainly responsible for the 4->5 upshift hence the 4->5 lockout in fail-safe mode, but it's not clear why it would effect the 2->1 downshift.

Made two attempts to clear via disconnecting battery for an hour+ each time. I think AAP may have attempted to clear it as well, but in all 3 cases, the CEL returned immediately at startup. AZ policy won't allow them to clear a CEL code, but they do give you a printout of the code with OEM descriptions rather than leaving you scrambling for something to write on.

Checking on line, part #35220-60010 is $130-$170. Whatever is wrong is most likely in the pan on the valve body; either the solenoid is actually damaged or I managed to disconnect or damage the wiring itself while reinstalling the pan. It was a bit of a juggling act to capture the dipstick tube while aligning the pan...all without touching the pan to anything besides the mounting flange...Toyota provided FIPG in lieu of a rubber/cork gasket despite the vehicle shipping with a gasket.

Plan is to call the dealer tomorrow for price to replace the SL2. The pan's got to be dropped even to run the FSM diagnostics on so I might as well go ahead and put that diagnostic labor $$$ towards the new part. Yes, I'm wimping out on a potentially straightforward DIY fix. I don't have the energy to fight the FIPG just to risk the same reinstall scenario if that's how I killed the SL2. Of course, it could have been a suspect part in the first place and letting it dry out finished it off. At least the pan didn't leak when I was done. ;-) AZ guy did mention that he had trouble several years ago finding someone who would just replace a solenoid without doing a tranny rebuild, but removal/installation of solenoid valves is covered in the FSM so I can't imagine Toyota will refuse.

Any thoughts on potential damage if I keep driving until the repair can be made? I'm assuming they don't have the part in stock so it might be a couple of days. I've already gotten in the habit of shifting to neutral to avoid the 2->1 downshift. There's still a bit of bump when going back from N->D, but not nearly as severe as a rolling downshift.

Thanks, guys!

-Brent

 

[bryceban]

Only risk I see is if you are not getting converter lock up it may add excessive heat. Whether it's enough to cause concern or not I am not sure.

 

[RiverWolf]

Originally Posted By: bryceban
Only risk I see is if you are not getting converter lock up it may add excessive heat. Whether it's enough to cause concern or not I am not sure.


Thanks. Talked to a local trans shop yesterday about doing the valve swap and he also seemed to think I'd be okay until we could get the solenoid replaced. Obviously, I'm going to keep babying it to avoid the hard 2->1 downshift.

I discovered this morning I was incorrect and I do still have TC lockup (the Toyota A750 trans will lock-up in 4th and 5th). I know the TC won't lock until speed exceeds 47-50 mph, but I thought I'd reached that condition Monday, but maybe I didn't check all of the boxes needed to allow TC lock. I've been altering my commute to stay in 45mph zones, but pushed on up close to 55 in one section this morning and felt/noticed the TC lock.

Can you believe the dealer tried to tell me it was a 6.x hour job? $600+ just for labor? With the A750, the valve body doesn't even need to be removed, just the pan and filter and then the all 7 solenoids are right in your face. Of course, he also said the book quoted the same time just fora pan drop. After I told him I could drain and drop the pan in about 30 minutes in my garage, including getting the vehicle up on jack stands, he said they could give me a better estimate if I brought it in to have someone look at it. Say what? Just go ask the mechanic, now. He also admitted they usually just replace the trans when someone comes in with a trans code. Wonder how long he'll have a job with that kind of honesty.

Currently, I'm waiting for a call from the local shop that the solenoid is in so we can schedule the service. The shop's owner quoted $300 total (fluid, solenoid, labor).

-Brent