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This thread documents a success story for those dealing with the famous early Gen 2 automatic transmission issue, ECU repair, and the sometimes-related P0770 code.

Background:

My sister has owned her 2001 Rav4 (2WD, U241E automatic transmission) since it was new. All maintenance was completed by the Toyota dealer. Last fall, the notorious ECU-induced automatic transmission issued started to manifest, apparently with the transmission refusing to get into third and slipping incessantly when it finally did get into third. However, the slipping was intermediate in occurrence.


Note: I didn't know my sister was having these troubles at the time, or else I would have recommended an ECU repair. If you are having this trouble right now, and it just started, spend the $72 and get your ECU professionally repaired and re-flashed, as that alone will very likely completely solve your problem if it has just begun (see my noted below).​

However, for my sister, it wasn't caught at first, because her daughter was a new driver, and perhaps she didn't clearly understand that such transmission behavior was abnormal, though she did report that the Rav was driving "weird" sometimes, especially on hills. They brought the Rav to a Toyota dealer, who somehow attributed the behavior to "the idle", repaired something having to do with "the idle" (I'm guessing it was a IAC clean or replace), charged them who-knows-what and sent them off. However, this (of course) did nothing to solve anything.

The last straw for my sister was when when her daughter called from the side of road, and the Rav was undriveable! Apparently, the ECU went absolutely crazy while her poor daughter was driving on a busy LA freeway, inducing some random shifting and terrifying power loss that could have caused an accident, completely terrified her, and landed her on the shoulder waiting for a tow truck.

The Rav apparently coded into some kind of "limp" mode, and then a "immobility" mode. It wouldn't even start, let alone move. I wasn't there, but I am told that they did manage to get it started eventually some weeks later, but it wouldn't get into any gear and the shift lever movement was described as feeling like "jelly" (which I am taking to mean that it felt as if the manual shift shaft in the transmission valve body was not moving properly, but I don't know).

She had the Rav towed to a Toyota dealer, who (of course) told her that she needed an entire new transmission, and a new ECU. They quoted her over $4,000 -- which is more than the car is worth. Then they told her the engine "was probably damaged too", so a new transmission might not even solve the problem and she probably needed "major engine work". She resolved to donate the non-running car and was expecting about a $500 tax write-off. She was justifiably a little upset.

When I learned about all this, I told her that what the Toyota dealer said was insane -- how could the Toyota dealer conclude such a extreme remedy without even getting the thing started? They MUST know about the ECU issue -- why didn't they at least try to install a different ECU and road test it? She said she didn't know, and she was just done with it, so she bought another car.

Since she was going to donate it, she said I could remove some parts to use on my other sister's '01 Rav4. I also wanted to see if I could get it running again. It took some trouble-shooting, but I did get it running -- and running like new! In total, it cost me just $150. This long post describes everything I did to get it back in action.


What worked -- eventually:
The Rav has only 122K miles on it, and all previous service was done by their Toyota dealer. The Rav is in very good shape overall.

1.) First off, I wanted to see if I could get an idea whether the transmission itself was damaged beyond repair, or if the ECU was just doing its notorious failure, or both:


I removed her original ECU and re-soldered the specific surface-mounted resistors and other components that are documented to have caused the ECU failure in the majority of cases like this. I simply followed a youtube video. My soldering skills are pretty bad, but with patience and a careful hand, I was able to at least do something, because when I re-installed the ECU, the car actually started, which it hadn't done in months. It also was driveable, but only up the 2nd:


There was a very high-pitched whine/whistle sound from the transmission area (driver's side). There was also a "crackly", "electric" sounding noise from this area. I couldn't tell if they were from different sources, or if they were just a sort-of "paired" noise. But at least it started.

Also, the transmission would finally get into P, R, N, D, 1, and 2, but when driving in D, it would slip incessantly when trying to shift to 3rd. If I then tried to put it in R (after a driving cycle when it couldn't successfully catch 3rd), it would operate abnormally -- either shudder and no power in R or it wouldn't get into R at all. However, if I shut it off and restarted it, it then would get into R normally. This told me it was still an ECU issue​
.​


2.) I sent the ECU off to be professionally repaired and re-flashed:


I used the services of "mandigital" on eBay. This vendor works out of Winona, WI, and offers a lifetime warranty on the repair. He removes the old resistors, re-installs new resistors, re-flashes the ECU with the updated software, and then tests the ECU in his own '01 Rav4. If you send him your ECU, there is no core charge and its just $72 (plus your cost to ship the board to him; he pays to ship it back). He had the board back to me in less than a week, and I was very pleased with the communication. In total with my shipping, it cost me $90.​


3.) I installed the repaired ECU in the Rav:


The Rav started up just fine, but the high-pitched whine/electrical noise from the transmission side was still there. I took it for a road test and was very pleased that it shifted right into 3rd, then 4th, and with a proper torque converter lock-up along the way. It drove normally again! But the noise was concerning and indicated that my work was not done.​


4.) Next I did a partial fluid change, by simply draining the fluid without removing the pan:


A simple drain removes about half of the ATF in the transmission -- most of the rest of the fluid will still be in the torque converter. It costs about $6/qt for Toyota T-IV ATF in the LA area, and I needed 3.5 quarts to refill it, so this step cost me $26 after tax. I would assume that it was the original ATF in there, since the car had just 122K miles, but I am not sure. The fluid had a very slight burnt smell, and while it was darker than I'd expect for that mileage, it wasn't tooooo bad, especially considering all the trouble the transmission had been enduring.


Note: To drain the the AT fluid, you simply need a 10mm hex head or a T-55 star head socket, and you just remove the drain plug and let the fluid drain. Replace the gasket (Toyota part #90430-A0003) and torque the drain plug to 35 ft-lbs, then re-fill with about 3.5 qt through the dipstick tube. Check the level when the AT fluid is at operating temperate, following the specific procedure outlined in the owner's manual.​


5.) I started the car, and the noise was still there, so now I am thinking clogged AT filter/strainer: I drove the car around, and within about about 15 minutes of driving, the transmission started slipping significantly in 3rd, and the torque converter was not locking out properly (this is evidenced by power loss after shifts, bizarre engine RPM, and no-shifts). Basically, the performance was actually worse than before the fluid change. I soon got a Check Engine light, so I pulled over and read it. It was P0770. Below is the note for this code from my '01 FSM:


P0770: Shift Solenoid E Malfunction (Shift Solenoid Valve DSL):
- Shift solenoid valve DSL is stuck open or closed
- Valve body is blocked or stuck
- Lock-up clutch​


I researched online for possible causes and found these:


- Low transmission fluid level
- Dirty transmission fluid
- Faulty shift solenoid 'E' valve
- Shift solenoid 'E' valve harness is open or shorted, Shift solenoid 'E' valve circuit poor electrical connection.
- electrical grounding issue (especially on Camry's, as documented on toyotanation forums)​


I wasn't happy to see this code, but I also wasn't surprised. It was now apparent that I needed to drop the AT pan and have a look inside.


6.) I drained the fluid again and removed the AT pan. Since I had just put so much new fluid in that day, I didn't want to waste it so I drained as much as I could directly back into the empty T-IV bottles and planned to strain it before refilling. I recovered about 3 quarts in this fashion, but lost the rest. I would still need to buy another 2 quarts because removing the pan removes more fluid.


The AT pan is easily dropped by removing the 18 bolts (10-mm) around the perimeter. You will find that they aren't very tight, and that's because they should only be torqued to 67 inch-lbs (note -- inch-lbs, not ft-lbs).

- If you live in a rust-prone area, you should soak these with PB Blaster before trying to remove.
- There will be quite a bit more fluid still inside the pan, so be careful when removing the pan.
- The pan gasket is not re-useable, so you will need a new pan gasket.
- On the inside of the pan, you will find three removable magnets. Note their location before you remove them to clean them, because you will need to place them back in the same spots.​

All the magnets had much more material than I would expect for the mileage, but again considering the trouble with the transmission, it didn't seem excessive. There were no small or large pieces or chunks of anything -- just very tiny metal bits on the magnets (the magnets looked fuzzy).


7.) Next, I removed the three bolts that hold the AT fluid strainer/filter to the valve body, and inspected the filter. I had thought I would be able to just clean the strainer with brake cleaner and re-use it, but it soon became apparent that it was far too contaminated. There was too much friction material on the filter for it be re-used.


Normally, I would have replaced the strainer with a Toyota strainer, but I didn't want to spend $65 on a new Toyota gasket and strainer when I might still have a bigger transmission problem. I rolled the dice and bought an aftermarket AT gasket and filter set at the local Pep Boys for $19. The aftermarket filter is a completely different filtration media: the Toyota strainer is a metal mesh, while the aftermarket is a papery or fiberous material. Also, the Toyota AT pan gasket is a cork-rubber gasket, while the aftermarket gasket was straight rubber.​

The filter condition was bad news, but also made me hopeful that the problem was fluid flow constriction and low pressure caused by the clogged filter. But I still wanted to test the DSL solenoid before closing up the transmission bottom.


8.) About the "Shift Solenoid E": this is the lock-up solenoid in the transmission. The part number for this transmission is Toyota #35290-32010 , and is located on the passenger side of the valve body, towards the rear. It is recognizable by its shape. The bad news is that you must remove the valve body to replace the DSL solenoid ("Shift Solenoid E"), if it is actually bad and if its the reason the P0770 code is showing and the torque converter is not locking up. However, the good news is that the solenoid is accessible to test without removing the valve body:


To test the solenoid, disconnect the battery and move it under the car where you can reach it. Then disconnect the electrical connection to the solenoid. Connect alligator clips to each contact on the solenoid, and apply power from the 12V car battery. If the solenoid is working, you will hear a click each time you cycle power, and little drops of ATF will drip out. (You can test any of the solenoids this way, though for the other solenoids you will need to introduce a 23 w bulb as resistance if using the 12V battery).​




I tested the solenoid, and it worked. I cycled it many times, and decided to leave it in place.


9.) I installed the new strainer/filter (torque the three bolts to 8 ft-lbs), then replaced the cleaned pan with the three magnets in place and the new gasket (torque the 18 bolts randomly to just 67 inch-lbs). I tightened the drain plug (torque to 35 ft-lbs), and refilled with ATF. I put about 5 quarts back in. I used the filter mesh from the old filter to strain the one-day-old ATF that I had caught in the bottles.


10.) I decided to check the engine grounds. I read on toyotanation that the U241E transmission in Camry's sometimes shows trouble due to bad grounds.


I removed the ground for the negative terminal of the battery and cleaned it up both ends with sand paper. I also replaced the ground that goes from the front of the engine to the chassis (passenger side) with a 6-gauge, 19 inch ground that I found at Walmart for $3. I replaced this ground because I couldn't find a ground directly from the transmission to the chassis, so I am thinking that the transmission-engine connection and this ground must be the effective ground for the transmission.​


11.) Then the moment of truth -- I started the Rav....and no more noise! She sounded like new! I was shocked and very happy. I listened with my stethoscope and everything sounded normal, at last. I let the Rav idle for 30 minutes. I used the Torque Pro app and my code reader to monitor the transmission temperature. I took it for a road test, and it drove like new -- no slipping, no failed lock-out, hit every shift, and ideal acceleration. It was like a new car!

I took the Rav over to San Pedro, which is a very, very hilly part of Los Angeles, and we drove it up and down the biggest hills there -- the Rav hit them like nothing! I monitored the transmission temps: with 88F ambient air, the highest temp I saw was 203F for a short time after hitting many steep hills (there are hills in San Pedro with grades over 30%). Once back on the freeway, the temp recovered to 178F. During normal driving over the next few days, it consistently stayed under 180F. My sister commented that it hadn't driven that well in a quite a while.

Next, I tested it for torque converter behavior on the freeway ramps, accelerating from low speeds and high speeds, and everything was working just fine. I drove it for about 300 miles over a few days, and was happy to have no slip re-occurrences at all, and no codes showing or pending. I tested it up to 80mph, and had totally normal operation and outstanding pick-up.

This little Rav has been saved from the salvage yard, and is back in action! I hope this long post helps others who might have this issue still. It makes me angry at Toyota all over again for their unbelievably poor handling of this situation and treatment of my sister, but I'm happy the Rav is back in play.
 

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GREAT SYNOPSYS

An excellent summary of your diagnoses and repairs of the transmission issues ... I had a similar (solenoid failure) in my Dodge Ram 2500 a few years back, finding parts and doing the repairs for a fraction of the costs at a dealer or transmission shop ... Now, if you know about any special tricks for bleeding hydraulics on an '01 manual, you can comment on my thread ...



https://www.rav4world.com/forums/88-4-2-faults-fixes/294093-cannot-shift-manual-5-speed.html
 

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hi...im having the same problem with my 2004 Rav4. Did you replace any of the solenoids you mentioned? Was it the cleaning of the Ground connection that fixed the problem?--Bob
 

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SUCCESS!!! on my end! I had the ECU re-soldered, but had one trans issue left over. The 2-3 shift was still a concern. Hesitates, harsh shift, hanging up, etc.
I went and bought the SL2 shift solenoid and installed it. [NO ENGINE CODES or SES LIGHT ON] Total Success here! Trans shift are smooth at all engine rpm's. Engine cold or warm! I ordered a reman solenoid for $47.00 delivered to my house. No kidding on the price. My dealer was at $386.00 and 3-5 days to get it. I put on about 70kms since, lots of stop and go to see what the shifts are like, all is good! I did shoot a GRAINY video of me changing the solenoid out, it is straight forward stuff, BUT!!! a warning here, there is a servo spring that is under pressure and will force the valve body downwards. LEAVE the 3 rear most bolts in, [loosened] and slowly undo the forward most bolt. The body will drop down, so be prepared for this. YOUTUBE: Stumpr1 is my channel. Hope this helps out! Cheers! Wayne S.
 

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Discussion Starter #5
SUCCESS!!! on my end! I had the ECU re-soldered, but had one trans issue left over. The 2-3 shift was still a concern. Hesitates, harsh shift, hanging up, etc.
I went and bought the SL2 shift solenoid and installed it. [NO ENGINE CODES or SES LIGHT ON] Total Success here! Trans shift are smooth at all engine rpm's. Engine cold or warm! I ordered a reman solenoid for $47.00 delivered to my house. No kidding on the price. My dealer was at $386.00 and 3-5 days to get it. I put on about 70kms since, lots of stop and go to see what the shifts are like, all is good! I did shoot a GRAINY video of me changing the solenoid out, it is straight forward stuff, BUT!!! a warning here, there is a servo spring that is under pressure and will force the valve body downwards. LEAVE the 3 rear most bolts in, [loosened] and slowly undo the forward most bolt. The body will drop down, so be prepared for this. YOUTUBE: Stumpr1 is my channel. Hope this helps out! Cheers! Wayne S.
Cool, stumper1! Here is a direct link to his videos on this transmission, for anyone who needs them:

Part 1:

Part 2:

Thanks for posting these videos, stumper1! I'm glad this worked for you.
 

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Thanks for the detailed info! I'm just starting to notice a problem with my 02 Rav 4WD with 115k miles. I'm the 3rd owner and I'm not too sure about the past repairs other than the ecu was reflashed around 95k. Note: I have no check engine light or codes showing. After taking a long 150 mile drive on the highway and returning to streets, I started noticing the trans will shift into 3 but only stay there for a few seconds and jerk into 4. It's so quick that I'm not even sure it's hesitating from 2-3 or 3-4. What is for sure is there is definitely a hesitation and definitely a jerking feeling and it's happening around the 3rd gear. When I turn the car off and come back to it a few hours later, it shifts fine along surface streets. But after warming up, the problem returns. It's also noticeable when picking up speed on the highway on ramp. When I try to floor it, it's as if the transmission has no clue what to do for a few seconds.

So now I'm at the drawing board deciding my options. First things first, I checked the ATF at operating temp and the fluid on the dipstick was a little bit past the "hot" notches. I'd say a few centimeters or .5 inch past. Along with what may be too much fluid, it also does look slightly brown. On a scale of 1-10 where 1 is clean and 10 is burnt black, I'd give the color a solid 5. My next thoughts are to do a fluid change/filter replacement and see how that goes. From there if the problem remains, my next step is to have the ecu repaired? What are your thoughts?
 

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Try doing a drain and fill and
Thanks for the detailed info! I'm just starting to notice a problem with my 02 Rav 4WD with 115k miles. I'm the 3rd owner and I'm not too sure about the past repairs other than the ecu was reflashed around 95k. Note: I have no check engine light or codes showing. After taking a long 150 mile drive on the highway and returning to streets, I started noticing the trans will shift into 3 but only stay there for a few seconds and jerk into 4. It's so quick that I'm not even sure it's hesitating from 2-3 or 3-4. What is for sure is there is definitely a hesitation and definitely a jerking feeling and it's happening around the 3rd gear. When I turn the car off and come back to it a few hours later, it shifts fine along surface streets. But after warming up, the problem returns. It's also noticeable when picking up speed on the highway on ramp. When I try to floor it, it's as if the transmission has no clue what to do for a few seconds.

So now I'm at the drawing board deciding my options. First things first, I checked the ATF at operating temp and the fluid on the dipstick was a little bit past the "hot" notches. I'd say a few centimeters or .5 inch past. Along with what may be too much fluid, it also does look slightly brown. On a scale of 1-10 where 1 is clean and 10 is burnt black, I'd give the color a solid 5. My next thoughts are to do a fluid change/filter replacement and see how that goes. From there if the problem remains, my next step is to have the ecu repaired? What are your thoughts?
Try doing a drain and fill to see if helps. Over filling is not good for the transmission plus it should be reddish pink not brown.
 

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Try doing a drain and fill and

Try doing a drain and fill to see if helps. Over filling is not good for the transmission plus it should be reddish pink not brown.
My thoughts exactly. Here are pics of the color and level of fluid at cold temp. Been sitting for a few hours now.
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6344C7DC-1446-45EC-90E9-8B0DF8988FFA.jpeg
C53D8E46-D2A5-425E-95B0-AC9B8822491F.jpeg
 

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Try using a quart of Lucas automatic transmission fluid conditioner with your Toyota T-IV fluid change. I swear by both, I only use Toyota automatic fluid. If the fluid change doesn't fix it, your ECU is flaking out and j suspect your problem will get worse. Spend 250. On getting it rebuilt by Circuit Board Medics. I've used them twice for my RAV4 shifting problems (2003 and 2004) These ECUs have defective fujistu solder that micro fractures over time. They also replace all the resistors on the ECU.
 

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Try using a quart of Lucas automatic transmission fluid conditioner with your Toyota T-IV fluid change. I swear by both, I only use Toyota automatic fluid. If the fluid change doesn't fix it, your ECU is flaking out and j suspect your problem will get worse. Spend 250. On getting it rebuilt by Circuit Board Medics. I've used them twice for my RAV4 shifting problems (2003 and 2004) These ECUs have defective fujistu solder that micro fractures over time. They also replace all the resistors on the ECU.
Will definitely do that. So let’s say for example I drain 4quarts of ATF. I put one quart of conditioner and 3 quarts ATF back in, correct?
 

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"Correctamondo" -Fonzie and Pulp Fiction. 1 qt Lucas AT conditioner and 3 qts of type IV or close to it, whatever the specs are.
 

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Discussion Starter #12
My thoughts exactly. Here are pics of the color and level of fluid at cold temp. Been sitting for a few hours now.
The fluid doesn't look that bad to me. Also, you do not check the ATF when the transmission is cool -- you must check it when the trans is warm. This is the procedure:

1.) Warm up the transmission fluid by driving around for at least 10 minutes.
2.) Stop the vehicle on a level surface, and leave it running but in Park.
3.) Pop the hood, and have a paper towel at the ready.
4.) Get back inside, engine still running, and shift from P to R to N, etc, all the way down to L, stopping for about 1 second in each. Then, shift from L to 2, wait one second, then 2 to D, etc, back to P.
5.) Once in P, get out and quickly pull the trans dipstick, clean it, and re-insert it; leave it in for a couple of seconds, then remove it and look -- what you see on the dipstick should be a fluid level between the notches on the "hot" side.

Regarding the Lucas additive: I would not suggest using any additive. Use Toyota T-IV only, no additive unless you're totally out of other options. Hopefully when you check your fluid using the "hot & engine running" procedure, you'll see that it will be at the right level.

You said that you have no CEL and no codes waiting, either -- so you did scan it? I ask because sometimes the P0770 hides for a little while before throwing the CEL, but it will show as a pending code if you use a scanner.

On the ECU: the ECU issue requires more than a reflash for remedy -- it requires a reflash and a proper repair of the inadequate factory soldering on several resistors. I would send your ECU in for a full repair: you don't have to pay $250 because mandigital on ebay will still do it for around $90 ($73, plus your shipping costs to him):


That ECU needs to be done, no matter what, so I would start there (unless you know for a fact that the ECU was previously repaired or replaced and not just reflashed).

Your Rav4 is very low mileage: this issue is mileage-related, because it has to do with vibrations inducing failure of the soldering on the ECU. I saw it happen 6 years earlier on a higher mileage Rav....then 6 years later, it happened around the same mileage on another Rav (both '01's). Mileage was around 120K miles.

After you get the ECU repaired, and re-installed, see if you have any issues. If you don't, then just do a drain and refill with Toyota TIV. If you still have some little issues, when drop the pan and replace the filter, and cycle the solenoid as shown at the top of the post. It is a very easy job and can be done in less than an hour. Check your fluid level before you start any drain and make sure that it is correct, and then measure everything that you drain. Refill with the same amount. ATF expands with heat, so best to measure the fluid when its at room temp and refill with the same amount at room temp.

In the meanwhile, don't drive it because the issue can get worse rather suddenly and you might find yourself in a scary situation (ie, trying to make a left against traffic, trying to merge, etc).
 

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The fluid doesn't look that bad to me. Also, you do not check the ATF when the transmission is cool -- you must check it when the trans is warm. This is the procedure:

1.) Warm up the transmission fluid by driving around for at least 10 minutes.
2.) Stop the vehicle on a level surface, and leave it running but in Park.
3.) Pop the hood, and have a paper towel at the ready.
4.) Get back inside, engine still running, and shift from P to R to N, etc, all the way down to L, stopping for about 1 second in each. Then, shift from L to 2, wait one second, then 2 to D, etc, back to P.
5.) Once in P, get out and quickly pull the trans dipstick, clean it, and re-insert it; leave it in for a couple of seconds, then remove it and look -- what you see on the dipstick should be a fluid level between the notches on the "hot" side.

Regarding the Lucas additive: I would not suggest using any additive. Use Toyota T-IV only, no additive unless you're totally out of other options. Hopefully when you check your fluid using the "hot & engine running" procedure, you'll see that it will be at the right level.

You said that you have no CEL and no codes waiting, either -- so you did scan it? I ask because sometimes the P0770 hides for a little while before throwing the CEL, but it will show as a pending code if you use a scanner.

On the ECU: the ECU issue requires more than a reflash for remedy -- it requires a reflash and a proper repair of the inadequate factory soldering on several resistors. I would send your ECU in for a full repair: you don't have to pay $250 because mandigital on ebay will still do it for around $90 ($73, plus your shipping costs to him):


That ECU needs to be done, no matter what, so I would start there (unless you know for a fact that the ECU was previously repaired or replaced and not just reflashed).

Your Rav4 is very low mileage: this issue is mileage-related, because it has to do with vibrations inducing failure of the soldering on the ECU. I saw it happen 6 years earlier on a higher mileage Rav....then 6 years later, it happened around the same mileage on another Rav (both '01's). Mileage was around 120K miles.

After you get the ECU repaired, and re-installed, see if you have any issues. If you don't, then just do a drain and refill with Toyota TIV. If you still have some little issues, when drop the pan and replace the filter, and cycle the solenoid as shown at the top of the post. It is a very easy job and can be done in less than an hour. Check your fluid level before you start any drain and make sure that it is correct, and then measure everything that you drain. Refill with the same amount. ATF expands with heat, so best to measure the fluid when its at room temp and refill with the same amount at room temp.

In the meanwhile, don't drive it because the issue can get worse rather suddenly and you might find yourself in a scary situation (ie, trying to make a left against traffic, trying to merge, etc).
Thanks for the detailed info I really appreciate it.

Quick update: I decided to jump the gun and get a rebuilt ecu from circuit board medics shipped overnight because I need to be back on the road sooner than later so I really need to get this taken care of. I got the ecu in the mail today and when I went to pull the ecu in my Rav... out came a rebuilt ecu from, you guessed it, circuit board medics! I was pretty perplexed and it was clear that one of the previous owners already had this done and who knows when. I went ahead and replaced it with the new rebuilt ecu anyways, and followed all the procedures of installing and road testing to re learn shifts. After an hour or so of driving, it was driving great. Even the idle felt amazing. But alas, the 2-3 gear knock/hang up started to come back. Not hard, but it would be there every now and then. It takes even longer now to engage R. A full 2 seconds. So now I’m at a loss of what to do with the circuit board medics “repaired” ecu. If I return it, could I send it off the original one to mandigital still? Worth it? Do I continue with a drain and fill or full atf pan drop and filter change? I’ll check the fluid again in the morning and follow your steps.
 

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Discussion Starter #14
Oh man, what a surprise that must have been!

Are you getting any pending codes or an actual check engine light after the recent driving? You'll need a scanner to see if there are pending codes, AutoZone can help with that for free if you don't have a scanner. A pending code won't throw a check engine light.

Would you say that the performance deteriorated as the transmission warmed up, or did you notice any other events that might have prompted it (meaning today when it went from driving well to not driving well)?

If you're still not getting any codes and there are no hidden/pending codes, then I would drain it, drop the pan, and replace the filter. If you have the original filter in there, it needs to be replaced anyway. It is a very simple job, but definitely use a 1/4-in drive torque wrench because you don't want to over-torque the filter bolts or then pan bolts (torque is above in the long post, it's very low and in inch-lbs).

A pan drop will replace about half of the total amount of ATF in the system, and if your filter was clogged, the combination of new filter and fluid should make a difference. If it doesn't, then the next look would be at replacing that solenoid (like stumper1 above did). You might want to cycle it a few times when you have the pan off.
 

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Oh man, what a surprise that must have been!

Are you getting any pending codes or an actual check engine light after the recent driving? You'll need a scanner to see if there are pending codes, AutoZone can help with that for free if you don't have a scanner. A pending code won't throw a check engine light.

Would you say that the performance deteriorated as the transmission warmed up, or did you notice any other events that might have prompted it (meaning today when it went from driving well to not driving well)?

If you're still not getting any codes and there are no hidden/pending codes, then I would drain it, drop the pan, and replace the filter. If you have the original filter in there, it needs to be replaced anyway. It is a very simple job, but definitely use a 1/4-in drive torque wrench because you don't want to over-torque the filter bolts or then pan bolts (torque is above in the long post, it's very low and in inch-lbs).

A pan drop will replace about half of the total amount of ATF in the system, and if your filter was clogged, the combination of new filter and fluid should make a difference. If it doesn't, then the next look would be at replacing that solenoid (like stumper1 above did). You might want to cycle it a few times when you have the pan off.
Ok so I did a lot of things yesterday. First things first I scanned for codes again which came up nothing. So no codes. The issue is definitely a 2-3 shift hangup/kick and it’s pronounced when it’s warmed up, however I do feel it when it’s cold. I got T-IV fluid from the delearship, new gasket and filter, and went on with doing the change. Ended up replacing just about 5quarts. The previous filter didnt look bad and to be honest I couldn’t figure out how to properly test the solenoids. I’m very much a beginner at all of this, hah. Anyways, I let the car idle for a bit and cycled from P,R,N,D, etc. Checked fluid level and took her for a 10-15min ride. Nothing, no issues and everything felt great. Came back and cleaned up. Got back in to take it to get gas, and then it was back to normal: 2-3 shift issue. Not worse, not better, just like before. Nothing changed. After cursing at the car for a bit as I was driving back home, I thought, well.. it must be that damn shift solenoid. I’m feeling a little defeated at the moment but slowly getting back up.
 

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Another update and long story short: I replaced the SL2 solenoid like Stumpr1 did. Bolted everything back up, warmed up car, cycled through gears, and went for a drive. Once again, everything was fine in the beginning but once the transmission warmed up after about 15-20 min of continuous stop and go driving the problem came back. It's a very specific jolt from gear 2-3. It slides into 3 and then jolts in to place. The harder I accelerate the harder the jolt. I don't know what else to do other than replace all the solenoids and cross my fingers. And if that doesn't do anything, I'm ready to throw the car at a transmission shop and expect a $2500+ bill...
 

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Another update and long story short: I replaced the SL2 solenoid like Stumpr1 did. Bolted everything back up, warmed up car, cycled through gears, and went for a drive. Once again, everything was fine in the beginning but once the transmission warmed up after about 15-20 min of continuous stop and go driving the problem came back. It's a very specific jolt from gear 2-3. It slides into 3 and then jolts in to place. The harder I accelerate the harder the jolt. I don't know what else to do other than replace all the solenoids and cross my fingers. And if that doesn't do anything, I'm ready to throw the car at a transmission shop and expect a $2500+ bill...
What a headache! And you are sure that your transmission fluid level is correct, right? You should have put about 5 quarts in from the pan drop (check the fluid level when its warm, engine running, after shifting through each gear). And you still have no check engine lights or codes?

Have you checked your engine grounds, as mentioned in #10 in the original post? What did your magnets look like on the pan -- anything scary?
 

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What a headache! And you are sure that your transmission fluid level is correct, right? You should have put about 5 quarts in from the pan drop (check the fluid level when its warm, engine running, after shifting through each gear). And you still have no check engine lights or codes?

Have you checked your engine grounds, as mentioned in #10 in the original post? What did your magnets look like on the pan -- anything scary?
Yes the fluid level is correct. I replaced around 5 and a quarter fluid after replacing the solenoid. I’ve checked it each time on my most recent test drives and exactly as you directed. One things for sure is it only acts up after at least 20-30minutes of driving so when the transmission and the fluid are fully warmed up. The magnets did look pretty “fuzzy” but I didn’t see any scary worth chunks of metal. Attached is a pic. It shifts really smooth before the transmission fully warms up. Feels great actually, but then goes back to the 2-3 hangup. I’m not sure how to check the grounds. Any links or pictures I can look at?
145964
 

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The magnets look a little fuzzier than usual, but they look about what my sister's magnets looked like. I think that your observation regarding the heated-up transmission fluid is important: it seems to be misbehaving when the transmission fluid is warmer -- but, it is possible that there's another piece of the puzzle. I was reading recently about some Nissan transmissions which were experiencing a similar thing, and it was the solenoid pack, but the computer was able to re-set the solenoid positions once the ECU was shut down (engine off), however after running for a while, the solenoids stopped responding.

So, maybe try this: drive around and get the fluid warm enough till it starts acting up again. Then, shut off the engine, wait 30 seconds (it won't be long enough to make a big difference in fluid temp), and restart. See if the issue returns. That might help you trouble shoot if it is a solenoid sticking issue or a "fluid warm" issue.

What did you do with the other Circuit Medics ECU? Have you swapped that, just to see?
 

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The magnets look a little fuzzier than usual, but they look about what my sister's magnets looked like. I think that your observation regarding the heated-up transmission fluid is important: it seems to be misbehaving when the transmission fluid is warmer -- but, it is possible that there's another piece of the puzzle. I was reading recently about some Nissan transmissions which were experiencing a similar thing, and it was the solenoid pack, but the computer was able to re-set the solenoid positions once the ECU was shut down (engine off), however after running for a while, the solenoids stopped responding.

So, maybe try this: drive around and get the fluid warm enough till it starts acting up again. Then, shut off the engine, wait 30 seconds (it won't be long enough to make a big difference in fluid temp), and restart. See if the issue returns. That might help you trouble shoot if it is a solenoid sticking issue or a "fluid warm" issue.

What did you do with the other Circuit Medics ECU? Have you swapped that, just to see?
Wow good call. I’ll try trouble shooting that in the morning. So when you say solenoid pack, are you referring to all of them together? Or another unit controlling all of them. I installed the CBM ecu I purchased and the problem was still there. I drove it around until the ecu relearned the shifts and then after 30min or so, the issue came back. So I called them and let them know and they recommended returning it and replacing the old CBM ecu as they said they stand by their work and it’s highly likely another issue. The original repaired ecu is installed now.

Also I just wanna say thanks for sticking around and helping me out. Before this month, I barely knew how to change my oil and now I’m pulling out solenoids in the valve body lol! There’s a silver lining in everything and I’m learning so much.
 
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