TWIMC: The district rep called me today and told me the backordered solenoid valve came in today and was ready for install. He said it was the primary valve that controls the main pump (as he put it), but understand he is not a field tech. (More like a firefigher). When the dealership calls back to schedule the installation, I will try to find out if there is some kind of secret re-calibration code, or if he has heard anything regarding an updated TSB.
Some people are noticing the hesitation on test drives or very soon after purchase, so unless the factory is overfilling transmission fluid, then I doubt this is the problem with every hesitating Toyota. I don't doubt that it was this guy's problem, but I just don't see how it could be for all of those experiencing the problem.
possibly for climate control which is a non-critical function (sorry florida residents).
definitely not ECU/TCM!
unless your company reverse-engineers the firmware, and even if you could do that accurately, you have only a SWAG of an idea of the design constraints and the failure modes anticipated by the engineering team that developed the firmware that is processing the various inputs, and generating the various outputs.
look, it's not like you'd be replacing one sensor with an equivalent sensor (electrically and physically characteristic-wise). you'd be attempting to apply a transformation to potentially multiple sensors, or actuator outputs, depending on your "solution".
no. i think some regulatory agency, if not the manufacturer would put your company in it's place. if not - they should.
I was not proposing that my company would dive headlong into this engine hesitation morase. I was simply trying to indicate that there are other ways to approach this rather than actually modifying the embedded ECU code.
For instance if the problem really is the result of the SLT solenoid's "plunger" not moving to the proper position according to the PWM signal applied then it would be relatively easy to build a calibration table with the correcting adjustments for a given solenoid valve and then modify the PWM signal accordingly.
Been there, done that.
But then I would have never attempted to use an electrically actuated solenoid as a linear servomotor, positioner, "open-loop", for "minute" and "precise" positioning without first building a calibration table specific to each individual solenoid.
Climate Control....Non-critical....???
NOT!
But you are mostly correct, were it not for the fact that the ability to quickly defog/demist the interior surface of the windshield, and hopefully help to keep it defogged, is an integral function of ALL automotive climate control systems, automatic or manual.
And by the way, there is a company that can provide you with a complete aftermarket controller for your automatic transmissions.
wwest- is it possible that Powertrain Control Solutions has the "secret" recalibration code that would allow our transmissions to shift (and downshift) "normally"? If so, would it be safe to assume it would void the Toyota warranty?
Just checked the tranny fluid, and I am stunned. It looks like it is filled about 1/2 inch past the deepest notch on the dipstick. I am taking it in immediately to see if I should drain some (fluid).
wwest...i'll stand by my assertion that the climate control is not a critical function, but i don't want to argue semantics.
sure, there are ways to "get in there" and make modifications to an otherwise "closed" system, but like I said, it is a risky proposition.
i'll also stand by my assertion that if you mod a vehicle with something like you pointed to: PCS (and I note there appears to be a product for the A340E, A343E, and A650E transmissions), then I think you effectively void your Toyota warrenty, unless, the product is approved by the manufacturer, which I highly doubt.
I'm probably wrong about their work being regulated then.
For customized vehicles, I can see it, but for production vehicles, I'm really quite surprised it exists, and further surprised that an end-user can do the configuring. They may make it very easy, and also easy to mess things up or get yourself into trouble.
Just left an independent repair shop where we checked the tranny fluid. He said it looked to him that my car was about a quart high. I will certainly bring this to the attention of the Toyota dealer on my visit tomorrow.
When would it have been over-filled - at the factory?
Would overfilling tranny fluid really cause these problems?
Don't get the fluid drained and solenoid replaced at the same time or we will never know which one remedied your problem (if either one should fix it).
OOPS!! I checked the oil level, not the tranny fluid...looks like the tranny dipstick should be more toward the back of engine. I found this AAA site with some useful info on how to check it, hope you can read the ultra-fine print: link title Note that you want to check the fluid hot (after 10 minutes of operation) and after moving the shifter through all forward and reverse gears with the engine running (don't burn yourself on hot engine parts). I'll post up as soon as I can figure out how to do this on my Camry. Since bkinblk had to bring it in to get the level checked, I think I probably will have to also, as I am no mechanic. Thanks for posting up your level info bkinblk!
So, your choice, a continuing Toyota transaxle warranty along with a transaxle ECU that occasionally puts your life at risk and for which Toyota has no fix or an aftermarket device that corrects the transaxle shifting flaw and no Toyota warranty?
What is the worse case cost of repairing a catastrophically failed transaxle vs a hospital stay or even worse a funeral?
The trans dipstick is orange (not yellow), and has a clasp around the top (to prevent it from backing out). As I mentioned, I checked the fluid level and was alarmed at how high it was. This morning, I took the car to an independent repair center and he confirmed that the fluid looked about a quart too high. He suggested I take it to Toyota and have them confirm (IN WRITING) that the fluid was filled too high at the factory, (keep in mind, the car has only 2500 miles). I think his suggestion was an excellent one, for obvious reasons. scoti1, it is unfortunate that we won't be able to tell which issue, if any, corrects the shifting problems, the solenoid valve or the transmission fluid. However, I have to cover my posterior on this one. Tomorrow morning, I drop the car off the pick up a free rental car. I am thankful that the regional DSPM has been very responsisve to all of my concerns.
wwest, you read this on the PCS site I'm sure: >>> Transmission Controller Software Release
PCS apologizes for the delays in delivering our software version 2.0.0 for the Automatic Transmission Controller. Due to a large amount of customer feedback and more information regarding the newest transmissions we have been adding many more features and functions. With all of these new features, we need to fully test the software and firmware so that PCS customers receive the outstanding reliability PCS has demonstrated in the past. We thank you for your patience and we will continue to work hard on this software and firmware to deliver PCS customers the best Automatic Transmission Controller on the market. >>
Now I imagine that if you bought one of their systems and you experienced a problem, providing you described it well enough, maybe supplied them some data from an OBD-II interface, you might actually get a quicker response that with the OEM. Then again, maybe you wouldn't. Whose to know?
I see your point. Maybe I'd try my vehicle mod'ed with one of these devices if I had no recourse (like crazy upside down) and had some extra $$$ to spend (not likely if the former), but during the warranty period? I don't think so. So then, I, Mr. Consumer would be stuck for the first what 36K/3yr with a poorly performing transmission unless I wanted to void my warrenty.
Call the company up and find out what they think the OEM position will be.
Now then, if I personally (me thinking out loud) had a poorly operating vehicle and I definitely wanted out, I'd get one of the OBD-II interfaces for $120 or so that could scoop real-time data as I drove. It's objective and most likely non-refutable if properly presented.
I'd try that route before I tried mod'ing the vehicle.
Anyway, if you're going to go all geek on your vehicle, you might as well get one of the interfaces, that way you can figure out if you got the mod'ed TCM set up the way you really want it anyway.
Come on wwest, got about $1K to toss at your issue?
I think I have proven that I have taken a pro-active approach to correcting the problem of an IMHO- faulty transmission (software-firmware-whateverware). Exhibit A: I immediately, (3 days after purchase, notitified the dealer that my car had a horrible transmission. I supplied him with supporting documentation. Exhibit B: I was the first to mention the Autoblog. com information regarding the Wade Hoyt quote in the Post-Gazette. Exhibit C- I notified posters about the updated Lexus TSB regarding re-calibration. Exhibit D- I took my car to a Lexus dealer to see if I could implement the calibration. Exhibit E- I telephoned Wade Hoyt in New York and corresponded 4 times by E-mail, trying to resolve this issue. Exhibit F- I contacted my local regional Toyota rep to address the issue, who, in response, scheduled an appointment for a solenoid valve replacement (tomorrow). I have updated this forum continually with any PERTINENT and RELEVANT information that I have discovered. My appeal to all habitual posters is this: I suggest you take a pro-active postition in order to help everyone find a solution to this problem, instead of speculation, pontification, hypothesis, theories, and a general REACTIONARY approach that doesn't necessarily help anyone who is extremely frustrated with the results of the second largest financial decision of their life; the purchase their automobile. Signed bknblk- aka- extremely frustrated
Listen to bkinblk...The tranny dip is NOT yellow. The oil dip is. Never check fluid levels in a dark garage..
I checked my 2005 Camry manual and didn't find a peep about how to check tranny fluid or where the stick was...but the orange tranny stick on the 3.3 is actually just behind the right side of the radiator (oil is left). The fluid was strawberry red color and on 3 checks it tape measured 3/4" above the top cutmark. (there are 2 cuts to mark the low range and 2 more to mark the high on the stick).
There is a lip at the end of the tranny stick that should be pointing down and slightly left when you insert it to get a good reading. I checked the level after about 15 minutes of driving and shifting through P-R-N-L1-2-3-D several times. The level was the same both with engine running and a minute or so after shutting it off. I re-checked the oil level today too (in daylight), the level was actually about 1/8" high, and it was changed at the dealer about 2k ago..
Thinking back, I didn't replace the tranny fluid on my '97 camry le until '02 or so, after 5 years. Since most of the hesitation problems have been on drivetrains of vehicles made from '02 to now I'd think most haven't had anything done tranny wise yet, after just 3 years.
I'd sure like to hear from a few more people with Toyota/Lexus V6 engines regarding their tranny fluid levels along with their year/model/engine/tranny info...
I am confused why you posted this, but want to reassure you that I, for one, greatly appreciate all the information you provide. But I think we all (well, at least all of the current posters) are coming from the same position -- how to deal with this (IMHO, too) faulty transmission. I don't think it is a contest of who can provide the best, most relevant, pertinent, etc. information. I learn from the different perspectives and advice. What isn't useful to me may very well be useful to the next guy.
Sorry, just frustrated I guess. Was in LA traffic all day yesterday, jerking, shuttering and hesitating. I would give the end of my finger (remember Wendy's?) to have my 2000 V6 back in my garage. Take the car in this morning, they'll have it until early next week. Wish it luck.
Good luck. I am hoping your loaner doesn't hesitate so that you can put that behind you (hopefully forever if the tranny draining and new solenoid work).
I am intrigued that your tranny fluid was overfilled. I did not think it was likely since the fluid was filled at the factory. Are they randomly overfilling? This could explain the randomness in the occurence of the problem, a little fact that has always bothered me. I just don't know enough to know if excess tranny fluid could lead to hesitation. Someone help me out here, wwest?, user777, anyone?
Is the trans fluid put in by machine or man at the factory? If by machine, then maybe the machine needs a re-calibration. Also, my car is American built (Vin begins with a 4), others are Japan built, (Vin begins with a J). I would be good to know if more American cars than Japanese cars are having the problem, or if it is accross the board.
I was going to check the Center for Autosafety site (http://www.autosafety.org) for you but the site is experiencing technical difficulty right now and I cannot access. This site takes complaints and includes VINs. I know there were a few hesitation problems reported here. So when the site gets back up, you may want to do a quick check on the Amercian versus Japanese question.
bkinblk: right. you've been doing everything in the proper manner. i think your results will be telling. if either or both the solenoid and tranny level are at root cause, it will give other owners true hope that their ride may improve without having to wait for a SW patch. much luck to you.
scoti1: did anyone get a new transmission in one of these vehicles and have their problem go away? i cannot recall with all the postings in the various related forums. if so, that may be indicative that the solenoid or the fluid or something other than ECM/TCM programming and sensors is at root cause.
Do any of you think, for a New York Minute, that if the hesitation were the result of fluid overfill Toyota wouldn't be all over that like fleas on a junkyard dog?
But to answer the question.
An overfill, if high enough, would result in frothing of the fluid, whipped up by the gear train until tiny air bubbles are thoroughly intermixed with the fluid. And yes, that would be highly detrimental to the functionally of the fluid since it would now be "compressable".
donx had the solenoid replaced (did not correct problem) and recently had the tranny replaced in his '04 Sienna. He also had an earlier ECM reprogramming (2003 time frame) that did not help. His posts are here and on the Sienna Problems and Solutions 2004+ board. I think he said his hesitation problem is solved. But I am not sure if the solenoid and transmission replacement were done solely for the hesitation problem. He had some additional problems that have not been reported by others with just hesitation (check engine light illuminated with error code for solenoid, said his van was not driveable). He also scanned his repair invoices after being challenged by another poster -- those may be more descriptive of the problems.
The Center for Autosafety site is back up but I don't have a lot of time to dig into it. I did check two recent Highlander complaints, both with hesitation, both with the "J" in front of the VIN. So, all I can say is that it does exist in those made in Japan.
wwest- we're exploring every possible angle. Dropped mine off at Toyota this morning and had the service manager check the tranny fluid in front of me. He was suprised and he noted (on the work order) that the fluid was 1" past the full notch on the dipstick. He said it definately could effect the performance of the transmission because of the greater pressure. They had Enterprise pick me up and put me in a Volvo S60. Man, Toyota's overall quality is really superior to that tin box-- IMHO. I will pick up my car tomorrow with less tranny fluid and a new solenoid valve. I also asked him to apply the new calibration code that was about to come out (who knows, maybe he'll make a couple of calls!) I will let everyone know tomorrow if I notice any immediate difference in the performance of the car.
From that post it sounds like overfilling could cause tranny damage, too. So if it were the problem, Toyota could be faced with major tranny repairs.
However, I do seriously question this being the cause:
1. It certainly seems like they would have figured it out long before production of 2005 models that are still experiencing problems. This problem is reported back as far as 2002 in the ES300, if I remember correctly.
2. It would be hard to believe that random overfilling is occuring at what could be several possible plant locations (maybe even in the US and Japan). There are several models impacted by this problem, all with the 5-speed tranny, but it is not consistent in all models. At what point in the production process is the tranny fluid added? Why would only the 5-speed tranny's be overfilled?
Maybe it is causing problems in a few vehicles, but as far as being the primary culprit in the Hesitation Problem, I don't think so.
It could even be bkinblk's problem since he has now documented that his nearly new vehicle was overfilled with transmission fluid.
Factory over-filling may be entirely intentional...
An over-fill, as long as it isn't to the level of being frothed by the spinning gears, may actually help prevent hesitation in some instances.
Over-filling the sump might be to prevent the transaxle's hydraulic pump from being "starved" during a tight hard turn at a reasonably high speed.
Sound vaguely familiar?
My "cut".
There is a rumor that the upcoming fix involves replacing the transaxle's SLT solenoid. That's the electrically actuated solenoid to which the engine/transaxle ECU applies a duty-cycle modulated 12 volt drive signal in order to "minutely" and "precisely" control the hydraulic pressure level used to actuate the clutches within the transaxle.
I had supposed quite some time ago that the root problem might have to do with the volume, capacity, of the transaxle's fixed displacement hydraulic pump.
Case in point....
"Hesitation seems to be much worse, more pronounced, with sudden throttle movement from idle to WOT.
The transaxle's hydraulic pump is directly driven by the engine via the torque converter's output mainshaft/case. The pump's volume capacity would obviously be at it's lowest with the engine at idle. Also, with the engine at idle the ECU's command to the SLT solenoid would be to only sustain minimum pressure.
In other words what fluid volume the pump is capable of pumping at idle is being "bled off" without any substantial pressure in reserve, no accumulator.
And now you suddenly go WOT!
In all likihood the ECU reacts immediately and orders the SLT solenoid to the maximum hydraulic pressure position. But now how many turns of the engine will it take pump enough fluid to build the pressure required to begin the newly commanded downshift sequence?
Begin the downshift sequence too early, before pressure builds, and there is not enough pressure to fully and firmly seat the clutches' frictional surfaces and you end up with premature transaxle failures as is happening with the earlier 4 speed transaxles.
And just suppose you have been a little indecisive about whether or not you can accelerate fast enough to safety merge into that upcoming opening in the high speed lane traffic and your indecisiveness is unconsciously reflected by foot action on the gas pedal. A few slight back and forth movements of the gas pedal could result in initiating an upshift and now you have definitely exhausted any "reserve" hydraulic pressure.
On the other hand.
You are not at all indecisive and when you decide to accelerate you depress the gas pedal to WOT but at a moderate rate.
The ECU will almost instantly release the torque converter lockup clutch and change the SLT command for high pressure and now as the engine RPM rises in response to the increasing throttle opening the transaxle's hydraulic pump flow volume will increase accordingly.
Why it might help alleviate the hesitation by disabling O/D or manually shifting into 4th gear.
The root cause of the "engine" hesitation seems to be that the Engine/Transaxle ECU's firmware is designed/specified such that it "wants" to upshift the transmission at any possible time.
Moving the transaxle into the highest possible gear would undoubtedly result in longer coastdown distances, less engine compression braking, and therefore improve the vehicle's emissions and fuel economy by some EPA/CARB measureable amount/level, however minor.
In my own personal opinion it may also be to reduce the potential for loss of directional control due to wheelslip caused by engine compression braking on FWD vehicles.
But be that as it may, if you can reduce the ECU's upshift options, disable O/D and manually downshift into forth, then it is much more likely that the shift sequence controller will not be in the process of commanding/controlling an upshift sequence and will be available to "command" the downshift that you need for acceleration when you next depress the gas pedal.
Someone on another forum had "argued" that the transmission upshifting when you release the gas pedal is exactly what it should do and always had done.
There is to me a great deal of truth in that statement so it sent me off wondering and then into some research.
I have earlier stated that my test drive a few months ago in a BMW X3 (definite rear torque biased AWD) resulted in my noting that when I released the gas pedal on the X3 at ~50MPH I got lots, LOTS of engine compression braking. On my 2001 AWD RX300 I get virtually none in the same circumstance.
So I went back and test drove the X3 again.
The difference is that if you fully release the gas pedal on the X3 the firmware seemingly "assumes" that your desire, intent, is to slow the vehicle somewhat rapidly. On the other hand in the X3 if you are in a "mid-gear, say for acceleration, and then you simply moderate, lift the gas pedal slightly, then it will upshift just as the RX300 does.
So the major difference seems to be the variation in what the two vehicles do with a (sudden?) fully closed throttle while in a middle gear.
Maybe overfilling would help compensate for fluid loss over time too.
I also see your logic in increasing fluid pressure through measured overfilling. It would have to be exacting though so fluid didn't get to the planetary gears, and foam.
Occasionally driving an auto RX-8, I'm always a little surprised by the torquey revs. They'll speed you up fast, but if you fall off the gas, they'll slow you down fast too.
I took a slow backstreets cruise in the 05 se tonight, and it is a lot smoother at low speed and coasts a lot easier that the X-8. The only thing I don't like is the occasional empty accelerator. You can cruise smooth for blocks in the se and then suddenly, at just any random corner, it wants to take a nap.
wwest- as you know, my car is currently at the Toyota dealership. Service called yesterday to tell me that because they need to pull the transmission to get to the valve body and replace the solenoid valve (SLT?), the car will be ready for me to pick up on Tuesday. He told me to keep the rental through the weekend. On a side note, If I remember correctly, I think the regional rep told me that the valve was the main valve that controls the pump-(does that make sense?). Anyway, to repeat a previous post, I find it very interesting that Toyota is moving forward with the fix without even driving my car. That tells me that they are very aware that there is a problem, and also it tells me that they believe they have an answer. We'll see. Meanwhile, the more I drive the underpowered S60 Volvo, the more I appreciate my Camry. It will be the perfect car WHEN they fix it!
Maybe your transaxle is different but I just had the sump pan and pump screen filter off of my 2001 RX300 and the valve body was right there ready to be dropped and replaced. I didn't actually count to be sure all of the control solenoids were also readily available but the ones I did note, at least three were also readily available.
If they really are pulling your transaxle then I suspect it to be more than just access to the valve body and/or solenoids. And remember that mine is a 4 speed and therefore different, we already know the five speed has a second pressure control solenoid, but it does give me cause to wonder......
We all have great interest in the results whatever....
I had the transmission software updated about three weeks ago on my '05 Lexus 330 -- so far, so good. It essentially eliminated the lag, but did not fix the sudden surge. So when I'm in stop-and-go traffic (which is nearly all the time), the car is more responsive than before, but still lurches forward rather than gradually. I share the negative feelings that others here have expressed about Lexus's response to the problem. The new software is an improvement (so far), and I feel lucky that it came just 4 months after I started complaining to them about the problem. I really feel for all you out there who have been fighting this for the past couple years. Well, I have learned my lesson, and will never buy a Lexus again. Back to Acura, or maybe Infiniti.
or scarey. depending on how you look at it. and to think we got on and off the surface of the moon with less computer resources...
maybe we as consumers should just say 'no' to some of this gratuitous, un-necessary automation. that's too many chips and code for me.
makes one appreciate a "dumb" (ha ha) cable linkage to the throttle doesn't it?
i wonder if it's possible that there will come a time in the future where low-tech cars are sought out by people because of their lower complexity and superior running reliability?
shifty - maybe edmunds should get some combination computer science / human factors experts to augment their staff..
Thanks for the update. Can you update again in a few weeks? I know previous software upgrades were reported by some to work initially, only for the hesitation to eventually return.
I think the solution to all this complexity will actually be disposable cars. You will not, in fact, fix them at all after warranty (much like a 5 year old computer or TV). If your Lexus doesn't work, you'll swap it out for a new one within the warranty period, kinda like Best Buy does with computers. Of course, you'll pay for that privilege somehow, don't you know.
Comments
definitely not ECU/TCM!
unless your company reverse-engineers the firmware, and even if you could do that accurately, you have only a SWAG of an idea of the design constraints and the failure modes anticipated by the engineering team that developed the firmware that is processing the various inputs, and generating the various outputs.
look, it's not like you'd be replacing one sensor with an equivalent sensor (electrically and physically characteristic-wise). you'd be attempting to apply a transformation to potentially multiple sensors, or actuator outputs, depending on your "solution".
no. i think some regulatory agency, if not the manufacturer would put your company in it's place. if not - they should.
very dangerous. very.
Maybe we have not "squeaked" loud enough to get any grease?
Is there anyone out there with enough legal contacts to know what "form" the official notification of consumer product troubles should take ?
I was not proposing that my company would dive headlong into this engine hesitation morase. I was simply trying to indicate that there are other ways to approach this rather than actually modifying the embedded ECU code.
For instance if the problem really is the result of the SLT solenoid's "plunger" not moving to the proper position according to the PWM signal applied then it would be relatively easy to build a calibration table with the correcting adjustments for a given solenoid valve and then modify the PWM signal accordingly.
Been there, done that.
But then I would have never attempted to use an electrically actuated solenoid as a linear servomotor, positioner, "open-loop", for "minute" and "precise" positioning without first building a calibration table specific to each individual solenoid.
Climate Control....Non-critical....???
NOT!
But you are mostly correct, were it not for the fact that the ability to quickly defog/demist the interior surface of the windshield, and hopefully help to keep it defogged, is an integral function of ALL automotive climate control systems,
automatic or manual.
And by the way, there is a company that can provide you with a complete aftermarket controller for your automatic transmissions.
See:
http://www.powertraincontrolsolutions.com
link title
link title
-Canadian ECU (USA)
gsb300, "Transmission problems with Lexus ES-300 ?" #716, 16 May 2005 11:00 pm
I know it was assembled about a month ago on April 25 in Kentucky.
Has Toyota been making any mid-year updates to help with the downshifting issue?
If they have a TSB to change the ECM program, are they putting that in the new cars, also? How do you tell?
Thanks for any info..I am just getting into this now!
sure, there are ways to "get in there" and make modifications to an otherwise "closed" system, but like I said, it is a risky proposition.
i'll also stand by my assertion that if you mod a vehicle with something like you pointed to: PCS (and I note there appears to be a product for the A340E, A343E, and A650E transmissions), then I think you effectively void your Toyota warrenty, unless, the product is approved by the manufacturer, which I highly doubt.
I'm probably wrong about their work being regulated then.
For customized vehicles, I can see it, but for production vehicles, I'm really quite surprised it exists, and further surprised that an end-user can do the configuring. They may make it very easy, and also easy to mess things up or get yourself into trouble.
Would overfilling tranny fluid really cause these problems?
Don't get the fluid drained and solenoid replaced at the same time or we will never know which one remedied your problem (if either one should fix it).
I found this AAA site with some useful info on how to check it, hope you can read the ultra-fine print:
link title
Note that you want to check the fluid hot (after 10 minutes of operation) and after moving the shifter through all forward and reverse gears with the engine running (don't burn yourself on hot engine parts).
I'll post up as soon as I can figure out how to do this on my Camry. Since bkinblk had to bring it in to get the level checked, I think I probably will have to also, as I am no mechanic.
Thanks for posting up your level info bkinblk!
What is the worse case cost of repairing a catastrophically failed transaxle vs a hospital stay or even worse a funeral?
This is NOT an offer!
you read this on the PCS site I'm sure:
>>>
Transmission Controller Software Release
PCS apologizes for the delays in delivering our software version 2.0.0 for the Automatic Transmission Controller. Due to a large amount of customer feedback and more information regarding the newest transmissions we have been adding many more features and functions. With all of these new features, we need to fully test the software and firmware so that PCS customers receive the outstanding reliability PCS has demonstrated in the past. We thank you for your patience and we will continue to work hard on this software and firmware to deliver PCS customers the best Automatic Transmission Controller on the market.
>>
Now I imagine that if you bought one of their systems and you experienced a problem, providing you described it well enough, maybe supplied them some data from an OBD-II interface, you might actually get a quicker response that with the OEM. Then again, maybe you wouldn't. Whose to know?
I see your point. Maybe I'd try my vehicle mod'ed with one of these devices if I had no recourse (like crazy upside down) and had some extra $$$ to spend (not likely if the former), but during the warranty period? I don't think so. So then, I, Mr. Consumer would be stuck for the first what 36K/3yr with a poorly performing transmission unless I wanted to void my warrenty.
Call the company up and find out what they think the OEM position will be.
Now then, if I personally (me thinking out loud) had a poorly operating vehicle and I definitely wanted out, I'd get one of the OBD-II interfaces for $120 or so that could scoop real-time data as I drove. It's objective and most likely non-refutable if properly presented.
I'd try that route before I tried mod'ing the vehicle.
Anyway, if you're going to go all geek on your vehicle, you might as well get one of the interfaces, that way you can figure out if you got the mod'ed TCM set up the way you really want it anyway.
Come on wwest, got about $1K to toss at your issue?
I checked my 2005 Camry manual and didn't find a peep about how to check tranny fluid or where the stick was...but the orange tranny stick on the 3.3 is actually just behind the right side of the radiator (oil is left). The fluid was strawberry red color and on 3 checks it tape measured 3/4" above the top cutmark. (there are 2 cuts to mark the low range and 2 more to mark the high on the stick).
There is a lip at the end of the tranny stick that should be pointing down and slightly left when you insert it to get a good reading. I checked the level after about 15 minutes of driving and shifting through P-R-N-L1-2-3-D several times. The level was the same both with engine running and a minute or so after shutting it off.
I re-checked the oil level today too (in daylight), the level was actually about 1/8" high, and it was changed at the dealer about 2k ago..
Thinking back, I didn't replace the tranny fluid on my '97 camry le until '02 or so, after 5 years. Since most of the hesitation problems have been on drivetrains of vehicles made from '02 to now I'd think most haven't had anything done tranny wise yet, after just 3 years.
I'd sure like to hear from a few more people with Toyota/Lexus V6 engines regarding their tranny fluid levels along with their year/model/engine/tranny info...
I am intrigued that your tranny fluid was overfilled. I did not think it was likely since the fluid was filled at the factory. Are they randomly overfilling? This could explain the randomness in the occurence of the problem, a little fact that has always bothered me. I just don't know enough to know if excess tranny fluid could lead to hesitation. Someone help me out here, wwest?, user777, anyone?
Still holding out hope for you, though, bkinblk.
cam2003, "Toyota Camry Owners: Problems & Solutions" #3368, 19 May 2005 11:27 pm
scoti1: did anyone get a new transmission in one of these vehicles and have their problem go away? i cannot recall with all the postings in the various related forums. if so, that may be indicative that the solenoid or the fluid or something other than ECM/TCM programming and sensors is at root cause.
But to answer the question.
An overfill, if high enough, would result in frothing of the fluid, whipped up by the gear train until tiny air bubbles are thoroughly intermixed with the fluid. And yes, that would be highly detrimental to the functionally of the fluid since it would now be "compressable".
link title
I've been shifting in manual (L1-2-3) lately in stop and go traffic. I don't get any hesitation that way.
Looking forward to hearing how your car runs when you get it back from the dealer. I just called the dealer and I'm taking mine in Monday morning.
Thanks for the tip on having the manager check the high tranny fluid level in your presence and then put it in writing on the service invoice.
However, I do seriously question this being the cause:
1. It certainly seems like they would have figured it out long before production of 2005 models that are still experiencing problems. This problem is reported back as far as 2002 in the ES300, if I remember correctly.
2. It would be hard to believe that random overfilling is occuring at what could be several possible plant locations (maybe even in the US and Japan). There are several models impacted by this problem, all with the 5-speed tranny, but it is not consistent in all models. At what point in the production process is the tranny fluid added? Why would only the 5-speed tranny's be overfilled?
Maybe it is causing problems in a few vehicles, but as far as being the primary culprit in the Hesitation Problem, I don't think so.
It could even be bkinblk's problem since he has now documented that his nearly new vehicle was overfilled with transmission fluid.
An over-fill, as long as it isn't to the level of being frothed by the spinning gears, may actually help prevent hesitation in some instances.
Over-filling the sump might be to prevent the transaxle's hydraulic pump from being "starved" during a tight hard turn at a reasonably high speed.
Sound vaguely familiar?
My "cut".
There is a rumor that the upcoming fix involves replacing the transaxle's SLT solenoid. That's the electrically actuated solenoid to which the engine/transaxle ECU applies a duty-cycle modulated 12 volt drive signal in order to "minutely" and "precisely" control the hydraulic pressure level used to actuate the clutches within the transaxle.
I had supposed quite some time ago that the root problem might have to do with the volume, capacity, of the transaxle's fixed displacement hydraulic pump.
Case in point....
"Hesitation seems to be much worse, more pronounced, with sudden throttle movement from idle to WOT.
The transaxle's hydraulic pump is directly driven by the engine via the torque converter's output mainshaft/case. The pump's volume capacity would obviously be at it's lowest with the engine at idle. Also, with the engine at idle the ECU's command to the SLT solenoid would be to only sustain minimum pressure.
In other words what fluid volume the pump is capable of pumping at idle is being "bled off" without any substantial pressure in reserve, no accumulator.
And now you suddenly go WOT!
In all likihood the ECU reacts immediately and orders the SLT solenoid to the maximum hydraulic pressure position. But now how many turns of the engine will it take pump enough fluid to build the pressure required to begin the newly commanded downshift sequence?
Begin the downshift sequence too early, before pressure builds, and there is not enough pressure to fully and firmly seat the clutches' frictional surfaces and you end up with premature transaxle failures as is happening with the earlier 4 speed transaxles.
And just suppose you have been a little indecisive about whether or not you can accelerate fast enough to safety merge into that upcoming opening in the high speed lane traffic and your indecisiveness is unconsciously reflected by foot action on the gas pedal. A few slight back and forth movements of the gas pedal could result in initiating an upshift and now you have definitely exhausted any "reserve" hydraulic pressure.
On the other hand.
You are not at all indecisive and when you decide to accelerate you depress the gas pedal to WOT but at a moderate rate.
The ECU will almost instantly release the torque converter lockup clutch and change the SLT command for high pressure and now as the engine RPM rises in response to the increasing throttle opening the transaxle's hydraulic pump flow volume will increase accordingly.
S..m...ooooo..th downshift, QUICK TOO!
The root cause of the "engine" hesitation seems to be that the Engine/Transaxle ECU's firmware is designed/specified such that it "wants" to upshift the transmission at any possible time.
Moving the transaxle into the highest possible gear would undoubtedly result in longer coastdown distances, less engine compression braking, and therefore improve the vehicle's emissions and fuel economy by some EPA/CARB measureable amount/level, however minor.
In my own personal opinion it may also be to reduce the potential for loss of directional control due to wheelslip caused by engine compression braking on FWD vehicles.
But be that as it may, if you can reduce the ECU's upshift options, disable O/D and manually downshift into forth, then it is much more likely that the shift sequence controller will not be in the process of commanding/controlling an upshift sequence and will be available to "command" the downshift that you need for acceleration when you next depress the gas pedal.
Someone on another forum had "argued" that the transmission upshifting when you release the gas pedal is exactly what it should do and always had done.
There is to me a great deal of truth in that statement so it sent me off wondering and then into some research.
I have earlier stated that my test drive a few months ago in a BMW X3 (definite rear torque biased AWD) resulted in my noting that when I released the gas pedal on the X3 at ~50MPH I got lots, LOTS of engine compression braking. On my 2001 AWD RX300 I get virtually none in the same circumstance.
So I went back and test drove the X3 again.
The difference is that if you fully release the gas pedal on the X3 the firmware seemingly "assumes" that your desire, intent, is to slow the vehicle somewhat rapidly. On the other hand in the X3 if you are in a "mid-gear, say for acceleration, and then you simply moderate, lift the gas pedal slightly, then it will upshift just as the RX300 does.
So the major difference seems to be the variation in what the two vehicles do with a (sudden?) fully closed throttle while in a middle gear.
I also see your logic in increasing fluid pressure through measured overfilling. It would have to be exacting though so fluid didn't get to the planetary gears, and foam.
Occasionally driving an auto RX-8, I'm always a little surprised by the torquey revs. They'll speed you up fast, but if you fall off the gas, they'll slow you down fast too.
I took a slow backstreets cruise in the 05 se tonight, and it is a lot smoother at low speed and coasts a lot easier that the X-8. The only thing I don't like is the occasional empty accelerator. You can cruise smooth for blocks in the se and then suddenly, at just any random corner, it wants to take a nap.
Maybe your transaxle is different but I just had the sump pan and pump screen filter off of my 2001 RX300 and the valve body was right there ready to be dropped and replaced. I didn't actually count to be sure all of the control solenoids were also readily available but the ones I did note, at least three were also readily available.
If they really are pulling your transaxle then I suspect it to be more than just access to the valve body and/or solenoids. And remember that mine is a 4 speed and therefore different, we already know the five speed has a second pressure control solenoid, but it does give me cause to wonder......
We all have great interest in the results whatever....
http://www.detnews.com/2005/autosinsider/0505/18/0auto-185628.htm
maybe we as consumers should just say 'no' to some of this gratuitous, un-necessary automation. that's too many chips and code for me.
makes one appreciate a "dumb" (ha ha) cable linkage to the throttle doesn't it?
i wonder if it's possible that there will come a time in the future where low-tech cars are sought out by people because of their lower complexity and superior running reliability?
shifty - maybe edmunds should get some combination computer science / human factors experts to augment their staff..
Thanks for the update. Can you update again in a few weeks? I know previous software upgrades were reported by some to work initially, only for the hesitation to eventually return.
I think the solution to all this complexity will actually be disposable cars. You will not, in fact, fix them at all after warranty (much like a 5 year old computer or TV). If your Lexus doesn't work, you'll swap it out for a new one within the warranty period, kinda like Best Buy does with computers. Of course, you'll pay for that privilege somehow, don't you know.