any engine/trans computer updates?

[riverwolf]

Anybody got access to a list of available "firmware" updates for the 4th Gens. Specfically, I'm looking for items related to transmission, torque converter, or cruise control functions. I have a June '03 build, if that matters.

Story behind the question. Several of us have brought this up over the years with no answers found. If the torque converter unlocks while on cruise control, it won't relock until you come off of cruise or change the set speed manually(bump accel up/down). I'm wondering if Toyota might have addressed this at some point, maybe even unintentionally, with a software update. Don't think about it much driving around coastal NC (flat), but we have a family vacation planned for the Smokeys in the near future, which means constantly futzing with the CC or driving without CC if I want to keep the torque converter locked.

Thanks!

-Brent

 

[eskimochaos]

Anybody got access to a list of available "firmware" updates for the 4th Gens. Specfically, I'm looking for items related to transmission, torque converter, or cruise control functions. I have a June '03 build, if that matters.

Story behind the question. Several of us have brought this up over the years with no answers found. If the torque converter unlocks while on cruise control, it won't relock until you come off of cruise or change the set speed manually(bump accel up/down). I'm wondering if Toyota might have addressed this at some point, maybe even unintentionally, with a software update. Don't think about it much driving around coastal NC (flat), but we have a family vacation planned for the Smokeys in the near future, which means constantly futzing with the CC or driving without CC if I want to keep the torque converter locked.

Thanks!

-Brent

I understand what your saying but can you give me an example. I drive 60 miles west each day to easter Pa and encounter some steep hills. How can I know if the Torque converter is locked?

Ill keep and eye out for it.

 

[riverwolf]

Re: Re: any engine/trans computer updates?

I understand what your saying but can you give me an example. I drive 60 miles west each day to easter Pa and encounter some steep hills. How can I know if the Torque converter is locked?

Ill keep and eye out for it.

It's easiest to see the TC engage once you hit 5th. Watch the tach as you accelerate and count the shifts. Once you hit 5th and settle on a cruising speed, you'll see the tach drop by 200-300 RPMs...that's the TC locking up. I think we can actually lock up in 3,4, and 5, but 5th is easiest to observe.

For the condition I'm describing:

1) set cruise on level road.
2) make note of current RPMs.
3) after climbing and/or descending a hill or overpass, observe tachometer again
4) if it's reading 200-300 RPMs higher than step 2, you're TC has unlocked and not relocked.

For an easy example, I've got a stretch of road on my daily commute that I can set the cruise at 60mph, which tachs at about 1800 rpms. Going uphill on a long high rise bridge, the TC appears to stay locked, but coming down the other side, where the wheels want to turn faster than the throttle setting needed to maintain set speed due to gravity assist, the TC will naturally unlock (normal operation to allow free spin). However, when the road levels back out and CC needs to apply throttle again to maintain speed, the tach now stays at 2100ish, indicating the TC never relocked. All you need is enough downhill incline that gravity "assists" the descent.

I, and the other folks who have noticed the same condition in the past, can do this consistently. Unfortunately, not enough people have noticed/contributed to the discussions to determine if it's limited to certain model years. Both the thread I started on this a couple of years ago and a similar one that I found later, never had more than 5-6 participants...most like yourself, just asking how to spot the condition and never coming back. Thus, my approach this time to see if anyone might have a list of s/w updates for the 4th Gens rather than specifically start a discussion about torque converters again.

-Brent

 

[toto]

I'm not aware of any TSB's for firmware upgrades for the 4Runner.
I know what you're talking about - the firmware for the trans with the 3.3L V6 used in Sienna/Highlander/RX330 went through several versions.

The dealer could check the version you have and see if there is a more current version. I have no idea what they'd charge you to do that. If you are there for other service, they might check it for nothing. If the firmware does need upgrading, the labor should be covered by the powertrain warranty if it's still in effect. (Downloading the firmware into the ECU is slllloooooowwww.) I don't know if a trans update would be covered by the federal emissions warranty or not.

 

[riverwolf]

I'm not aware of any TSB's for firmware upgrades for the 4Runner.
I know what you're talking about - the firmware for the trans with the 3.3L V6 used in Sienna/Highlander/RX330 went through several versions.

The dealer could check the version you have and see if there is a more current version. I have no idea what they'd charge you to do that. If you are there for other service, they might check it for nothing. If the firmware does need upgrading, the labor should be covered by the powertrain warranty if it's still in effect. (Downloading the firmware into the ECU is slllloooooowwww.) I don't know if a trans update would be covered by the federal emissions warranty or not.

Yep, pretty sure we checked AllData and the NHTSA and there didn't appear to be any TSB or complaints directly related to this. It's the kind of thing you have to be fairly OCD to even notice. Guilty as charged :nerd:

I do need to stop by the dealer this week to pick up some parts, but you know what it's liking talking to the service writers. Even if I can get them to understand what I'm asking and they can actually find a list of updates, there'll be some technicality that won't let them simply do the update without lots of $$$ diagnostics first. Wish I'd noticed this before my basic 3/36 ran out, I have doubts about the powertrain warranty covering it.

-Brent

 

[Kevin G.]

My new......

.......2008 Sport V8 2WD does NOT exhibit this fault.......it always returns to it's original RPM at cruise....TC locked-up again. A revision/upgrade for 2008??? It is my first T4R.

I've had vehicles, in the past, that would unlock, and downshift, all the time. Drove me nuts. Swore I'd never have another underpowered, or high-geared rearend, vehicle again........and I haven't.

Interesting subject.....

Kevin

 

[toto]

I do need to stop by the dealer this week to pick up some parts, but you know what it's liking talking to the service writers. Even if I can get them to understand what I'm asking and they can actually find a list of updates, there'll be some technicality that won't let them simply do the update without lots of $$$ diagnostics first. Wish I'd noticed this before my basic 3/36 ran out, I have doubts about the powertrain warranty covering it.

I agree that the biggest obstacle will be getting the people at the dealership to understand what you're talking about. They might be familiar with the trans issues a few years ago on Highlander and Sienna, so you could explain that it's like that.

If you can get them to understand it, doing it is easy. Toyota has switched from a handheld-based OBD II scan tool to a computer-based software tool (TIS Techstream). With the computer being on a wireless network, it's much easier for Toyota to upgrade the tool and put a wealth of information in the technician's hands. That system can easily pull the version number out of the trans ECU and see if it's the latest one. The technician doesn't need to have a list of versions.

You might also be right that there could be lots of excuses about not doing it. The dealer might have to determine it's necessary as opposed to just convenient. It should be covered by the powertrain warranty; the trans ECU controls part of the powertrain. I believe it could take 30-45 minutes to download, so you're looking at an hour of labor easily.

 

[riverwolf]

Went by the dealer this afternoon. Searching TIS for "ECU Update" and "TCM update" only turned up one ECU hit applicable to a 2003. It didn't really mention what was fixed in the update, but for $90 I can found out if it helps the Cruise Control/Torque Converter interface. Lucky me. I'll try to find time to schedule the update before my trip...what's another $90, right?

And to vent. A few weeks ago, while doing the diff/xfer fluids, I decided to do TSB BR004-06 since I was starting to really notice the random pedal firmness. Since I didn't discover the TSB until well after my 3/36 was gone, that meant springing for the $40 "upgraded" shim set myself. In the mean time, I've decided I've been putting off replacing the front rotors long enough...probably warped during the tire rotation the last time I let the dealer touch my truck 3 years ago. Decision made easier by discovering the Centric Premium rotors for only $54/each at RockAuto. Anyway, went by the dealer today to pick up the new pads for the brake job. Lo and behold, Toyota has changed the brake pads, at least the part number, and the new front pad kit now includes new shims which are different from both the originals and the updated 2 piece set from the TSB. Argh...that $40 wasted on the TSB shim kit would cover half the ECU update. They still have the old pad kit in stock, but it's the same price as the new kit with shims...kind of a no brainer decision. The new shims use adhesive to stick to the pad, no lubricant required...FWIW.

-Brent

 

[eskimochaos]

Went by the dealer this afternoon. Searching TIS for "ECU Update" and "TCM update" only turned up one ECU hit applicable to a 2003. It didn't really mention what was fixed in the update, but for $90 I can found out if it helps the Cruise Control/Torque Converter interface. Lucky me. I'll try to find time to schedule the update before my trip...what's another $90, right?

And to vent. A few weeks ago, while doing the diff/xfer fluids, I decided to do TSB BR004-06 since I was starting to really notice the random pedal firmness. Since I didn't discover the TSB until well after my 3/36 was gone, that meant springing for the $40 "upgraded" shim set myself. In the mean time, I've decided I've been putting off replacing the front rotors long enough...probably warped during the tire rotation the last time I let the dealer touch my truck 3 years ago. Decision made easier by discovering the Centric Premium rotors for only $54/each at RockAuto. Anyway, went by the dealer today to pick up the new pads for the brake job. Lo and behold, Toyota has changed the brake pads, at least the part number, and the new front pad kit now includes new shims which are different from both the originals and the updated 2 piece set from the TSB. Argh...that $40 wasted on the TSB shim kit would cover half the ECU update. They still have the old pad kit in stock, but it's the same price as the new kit with shims...kind of a no brainer decision. The new shims use adhesive to stick to the pad, no lubricant required...FWIW.

-Brent

After 500miles of highway this week I was able to mess with the cruise control and learn myself when the torque converter locks and unlocks. Every single time I put it in cruise on a straight part waiting for an incline. Each time the torque converter would remain locked going up and going down the hill. The revs didnt move I tried everywhere from 55 to 85 and it just wouldnt unlock.

Last night; however, there was no traffice so I was in cruise control 75 the entire way home. I got to one hill while on CC 75. The revs were 2250 before getting to the hill, going up the hill, the torque converter unlocked and reved to exatcly 2500rpm. After getting to 75 again, the torque converter locked and revs went back to 2250 (this is while still on the incline)

On the way down, it didnt unlock and the revs didnt move past 2250. So, I drove home 70 miles last night with CC on 75 the entire way. The toruqe converter locked up after accelerating to the needed speed each time - and no I didnt mess with the CC speed.

My $.02.

 

[riverwolf]

After 500miles of highway this week I was able to mess with the cruise control and learn myself when the torque converter locks and unlocks. Every single time I put it in cruise on a straight part waiting for an incline. Each time the torque converter would remain locked going up and going down the hill. The revs didnt move I tried everywhere from 55 to 85 and it just wouldnt unlock.

Last night; however, there was no traffice so I was in cruise control 75 the entire way home. I got to one hill while on CC 75. The revs were 2250 before getting to the hill, going up the hill, the torque converter unlocked and reved to exatcly 2500rpm. After getting to 75 again, the torque converter locked and revs went back to 2250 (this is while still on the incline)

On the way down, it didnt unlock and the revs didnt move past 2250. So, I drove home 70 miles last night with CC on 75 the entire way. The toruqe converter locked up after accelerating to the needed speed each time - and no I didnt mess with the CC speed.

My $.02.

I appreciate the effort, but it doesn't sound like your road conditions were quite right for verifying one way or the other if this "bug" is present in your '07. It's also not clear whether you have a 2x4 or 4x4...I've got a 4x4 V8.

I've never had a problem with the TC relocking after unlocking under load on cruise. As a matter of fact, that's how I force it to relock when it unlocks...cancel cruise then hit resume. This is essentially what you were seeing when inclines forced the cruise to call for more throttle and the computer didn't think there was enough torque with the lockup engaged.

It doesn't sound like your downhills were steep enough for the CC to back out of the throttle enough to force an unlock condition. Unlocking is normal operation on steep enough descents for any AT with a lockup TC...gravity takes enough load off the engine that no throttle is needed. The CC can't use brakes to control descent speed so it backs off the throttle input to try to maintain set speed with engine braking. In turn, the only way to allow the driveshafts/wheels to turn faster than the crank shaft is to disengage the TC lockup. The bug happens when the TC doesn't relock when the descent is over and CC gets back into the throttle.

This downhill unlock bug is a subtle, but distinct difference from unlocking/relocking to climb a hill, which seems to function normally for those of us who've noticed this. I didn't even recognize the difference myself until last summer on a business trip down to Atlanta. 7 hours (one way) alone in rolling terrain gives you lots of time to experiment. Prior to that, I'd only been aware that I was unlocking at some point on CC and not relocking, but hadn't found the trigger...assumed it was increased load until the ATL trip.

After reviewing TSBs, I skeptical that the ECM update the service guy found will help. It looks like it's probably the update associated with the revised Cats to get rid of the sulfur smell in '03-mid '05 models. However, assuming my VIN qualifies, I'm probably going to put in for the TSB since it's covered under the 8/80 emissions warranty...haven't noticed the sulfur smell a lot, but if it gets me an updated ECM under warranty, it's worth the trouble.

-Brent

 

[eskimochaos]

Well I'm commuting 600 miles a week to school for the next 10 weeks so ill have more time to try it out. I will def keep an eye on it going down the hill, perhaps ill try some different speeds.

I will be sure to let you know. Do I need to be on the highway to test this? Can I be on a 35mph road that I know is steep enough for my car to pick up speed based on gravity alone and test it there? Do you think this is an overdrive issue only or will it prevalent in other gears? Either way, ill report back.

 

[riverwolf]

Well I'm commuting 600 miles a week to school for the next 10 weeks so ill have more time to try it out. I will def keep an eye on it going down the hill, perhaps ill try some different speeds.

I will be sure to let you know. Do I need to be on the highway to test this? Can I be on a 35mph road that I know is steep enough for my car to pick up speed based on gravity alone and test it there? Do you think this is an overdrive issue only or will it prevalent in other gears? Either way, ill report back.

Ouch! I did a commute like that one summer...in a car without cruise control, no less. By the time second summer session was over, I was probably skipping more days than I attended each week. Fortunately, those credits only transferred back to my regular school as P/F instead of counting in my GPA.

IIRC, while the A750 can lockup in 3/4/5, it will only lockup at 50mph or faster so your local hill probably won't work. Once locked, I think you can slow down under 50 and stay locked, but I don't know how low you can go. 50mph in 5th with lockup is only 1500 rpms for me and stall speed for the TC is probably 1200 rpms or higher; that's not a lot of range to work with.

I've only observed it on major highways or intersates and until you just made me think about it, I'd never considered behavior with a lower gear so there are lots of variables left unexplored here. Just for giggles, since I have a bridge that's consistently repeatable at 60/5th (traffic permitting), I'll try to remember to run that stretch in 4th next week. Since engine braking will be more pronounced in 4th, it might not be steep enough to force an unlock, though.

-Brent

 

[eskimochaos]

Did some more testing today and it seems the hills that I drive over help with the descent when going around 55mph. Going up the hill at 55mph revs are around 1800. I noticed when gravity started taking over on the descent the TC unlocked and the revs dropped below 1500 to around 1300. I would lose a little speed and the TC would relock at 1800 to bring me back to 55mph. This happened a couple times over the course of the descent. At the end of the hill, my TC relocked and remained at 1800rpm until I quickly accelerated again to highway speed. (I looked silly with my hazards on getting passed by 18 - wheelers).


I want to make it clear what when the TC unlocked on the descent it appeared to almost go to neutral. It then relocked again to maintain speed after the descent.

I hope this helps. Ill take a video of it tomorrow and put it on youtube for you.

 

[eskimochaos]

Well here is the video. Sorry for the crappy sound and video but you get the idea. I started the vid about 3/4 away from the top of the hill and most of it is going down the hill. You can see the TC locked at 1800rpm while driving up it then when I get to the top it unlocks and goes to 1500rpm multiple times until the end when I accelerate to speed.

I start coasting around 25seconds.

Oh, and those awful noises are me hitting people.

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[eskimochaos]

Ill make a better video tomorrow with my Digital Camera.