Towing with a 200-series Toyota Land Cruiser (7 Viewers)

[skrypj]

Do you have a tool to tune that?

I'm not sure I would characterize any of this as an issue. It's normal for it to lock and unlock as it sees fit. Unlock is a tool to smooth out power delivery. It also works as a virtual gear between gears for more mechanical advantage. That the tranny fluid warms up is no big deal within the normal range. It will get to a threshold where the tranny ECU will get more aggressive about locking to manage temps. I've seen it lock all the way down to 2nd gear (on my 6 speed).

Agree heat is definitely generated by unlocking. It unlocks on downhills too under engine breaking. The other factor is how much power is being pushed through the tranny. Try pushing 350hp+ for minutes and yes, things get warm, even locked. I would also say to use RPM to your advantage. The party gets started at 3500 RPM. Relatively less combustion pressure for the same output at higher engine speeds, and more fluid circulating in the engine and tranny.

View attachment 3619212

Yes I have VFTuner.

I agree it’s not a huge deal but I haven’t even gotten into summer yet. I was hitting 240’s when it was 60F out. Yesterday I was high 230’s when it was 45F out.

You make it sound like there is a lot of intelligence behind the TC lockup which really isn’t the case. It’s just a table for each gear that determines lockup for a certain speed and accelerator position. 4th gear is set to never lock(the speed for all accelerator positions is set to 163 kph). Thats it. You might be right that there is some background coding to lock up the TC once it gets to very high temps but I have hit 250 and I don’t think I have seen that happen.

That said, there are TC lockup tables in the tune for a “tow mode”, which I don’t believe we can access, which does enable lockup in 4th gear.

It take 5 minutes to tweak the tune to lock the TC and flash it.

 

[linuxgod]

This is the same Toyota that says its lifetime trans fluid?

I can just tweak the tune slightly to make it lock up 3rd and 4th above 55mph and it will be a non-issue.

It’s lifetime if you don’t tow. If you tow or off-road you’re supposed to swap the 3-4 quarts in the pan every 60k

If you can tweak the transmission tuning, go for it. I’d love an option in the 6 speed where I could change the lock up and shifting when in ECT PWR to act as a real tow mode…

 

[skrypj]

It’s lifetime if you don’t tow. If you tow or off-road you’re supposed to swap the 3-4 quarts in the pan every 60k

If you can tweak the transmission tuning, go for it. I’d love an option in the 6 speed where I could change the lock up and shifting when in ECT PWR to act as a real tow mode…

VFTuner and HPTuners have been able to tune the 6 speed for years. VFTuner only recently released tuning for the 2016+ trucks.

 

[TeCKis300]

Yes I have VFTuner.

I agree it’s not a huge deal but I haven’t even gotten into summer yet. I was hitting 240’s when it was 60F out. Yesterday I was high 230’s when it was 45F out.

You make it sound like there is a lot of intelligence behind the TC lockup which really isn’t the case. It’s just a table for each gear that determines lockup for a certain speed and accelerator position. 4th gear is set to never lock(the speed for all accelerator positions is set to 163 kph). Thats it. You might be right that there is some background coding to lock up the TC once it gets to very high temps but I have hit 250 and I don’t think I have seen that happen.

That said, there are TC lockup tables in the tune for a “tow mode”, which I don’t believe we can access, which does enable lockup in 4th gear.

It take 5 minutes to tweak the tune to lock the TC and flash it.

Nice, show us more of the VFTuner. I assume you were able to unlock the ECU while also getting access to the tables.

To your point, it's a series of tables and logic steps, and I've seen them in action. Fortunately, except for the 302F ATF warning which is honestly commendable given the 15,620lbs weight level I'm towing at. I've been at this awhile and have been through all the routes you describe in the heat of summer. For a cruiser that is healthy and not modified in such a way that it impacts the cooling systems, it will take care of business without any help.

If you haven't come across this thread

Torque Converter Handling of Heavy Loads

Got to see the torque converter handling of heavy loads in action on a recent tow trip. Laden with 6 people and a 27' Airstream for a long 10-day trip, CAT scaled at 15,620 lbs. Ambient was 90F+ in areas. Combined with some big grades in the west, I was curious how the torque converter...

forum.ih8mud.com

 

[skrypj]

Nice, show us more of the VFTuner. I assume you were able to unlock the ECU while also getting access to the tables.

To your point, it's a series of tables and logic steps, and I've seen them in action. Fortunately, except for the 302F ATF warning which is honestly commendable given the 15,620lbs weight level I'm towing at. I've been at this awhile and have been through all the routes you describe in the heat of summer. For a cruiser that is healthy and not modified in such a way that it impacts the cooling systems, it will take care of business without any help.

If you haven't come across this thread

Torque Converter Handling of Heavy Loads

Got to see the torque converter handling of heavy loads in action on a recent tow trip. Laden with 6 people and a 27' Airstream for a long 10-day trip, CAT scaled at 15,620 lbs. Ambient was 90F+ in areas. Combined with some big grades in the west, I was curious how the torque converter...

forum.ih8mud.com

Here are the 4th and 5th gear lock/unlock tables:

Its not clear to me if the speeds are actual in KPH or MPH. VFTuner is not great about axis labeling.

 

[skrypj]

Nice, show us more of the VFTuner. I assume you were able to unlock the ECU while also getting access to the tables.

To your point, it's a series of tables and logic steps, and I've seen them in action. Fortunately, except for the 302F ATF warning which is honestly commendable given the 15,620lbs weight level I'm towing at. I've been at this awhile and have been through all the routes you describe in the heat of summer. For a cruiser that is healthy and not modified in such a way that it impacts the cooling systems, it will take care of business without any help.

If you haven't come across this thread

Torque Converter Handling of Heavy Loads

Got to see the torque converter handling of heavy loads in action on a recent tow trip. Laden with 6 people and a 27' Airstream for a long 10-day trip, CAT scaled at 15,620 lbs. Ambient was 90F+ in areas. Combined with some big grades in the west, I was curious how the torque converter...

forum.ih8mud.com

Also, I’m pretty sure what I am looking at is pan temps, not converter temps. I don’t believe OBDLink app has the PID for the converter temp for my 2018, just AT oil temp 1.

Is your thread saying you saw 266F torque converter temps but you were 230 pan temps while that happened? Because I’m pretty sure my pan temps have been up near 250. I was pulling into a 30-40 mph headwind at one point on my trip back in February and was running in 4th at 60 mph near WOT and my temps got up pretty high without even hitting a hill. Then I hit a big hill and I think that was when my AT oil temp 1 hit 249 or something.

There is an AT oil temp 3 in OBDLink but it’s screwy and scaling is def not right because it reads -40 when you start the truck.

 

[linuxgod]

Also, I’m pretty sure what I am looking at is pan temps, not converter temps. I don’t believe OBDLink app has the PID for the converter temp for my 2018, just AT oil temp 1.

Is your thread saying you saw 266F torque converter temps but you were 230 pan temps while that happened? Because I’m pretty sure my pan temps have been up near 250. I was pulling into a 30-40 mph headwind at one point on my trip back in February and was running in 4th at 60 mph near WOT and my temps got up pretty high without even hitting a hill. Then I hit a big hill and I think that was when my AT oil temp 1 hit 249 or something.

There is an AT oil temp 3 in OBDLink but it’s screwy and scaling is def not right because it reads -40 when you start the truck.

I'm pretty sure OBDLink and OBDFusion are the same app, it's just that OBDLink comes with dongles and has everything activated but OBDFusion is from the app store and charges for each PID. OBD Fusion definitely has both PIDs in the $10 Toyota Enhanced PID pack. I only have the 6 speed so I can't say which they are but I'm positive I've seen others with an 8 speed post the values for OBD Fusion.

Dash warning lights and ECU behaviors are triggered off the TC temp I believe. Somewhere around here I posted a snapshot from the FSM with the specific temps and scenarios that occur, but it's just over 300F before the warning light comes on the dash and the truck downshifts and starts locking the TC in lower gears automatically, and it goes off around 270F. My interpretation is that Toyota thinks anything under 270F must be OK since there's no warning and the transmission behavior is normal at that point.

I've had my pan and TC up around 248-249 before climbing Monarch Pass in 2nd gear with my trailer attached. Temps were actually a couple degrees cooler in 2nd than in 3rd, probably because the A/T fluid is pumped by engine RPMs so it circulates faster. If you can't stay locked it's definitely better to use a lower gear when climbing and get the engine revving in the 4k+ range.

 

[linuxgod]

Here are the 4th and 5th gear lock/unlock tables:
View attachment 3619341

Its not clear to me if the speeds are actual in KPH or MPH. VFTuner is not great about axis labeling.

That is awesome, I thought VFtuners could only do engine ECU, not transmission. Oh man I know what I want for my birthday next month!

Can you set the TC lock maps to only apply with in ECT PWR mode? (Or really is ECT PWR treated as a completely separate set of maps to program or is it layered over the base map?)

 

[skrypj]

I'm pretty sure OBDLink and OBDFusion are the same app, it's just that OBDLink comes with dongles and has everything activated but OBDFusion is from the app store and charges for each PID. OBD Fusion definitely has both PIDs in the $10 Toyota Enhanced PID pack. I only have the 6 speed so I can't say which they are but I'm positive I've seen others with an 8 speed post the values for OBD Fusion.

Dash warning lights and ECU behaviors are triggered off the TC temp I believe. Somewhere around here I posted a snapshot from the FSM with the specific temps and scenarios that occur, but it's just over 300F before the warning light comes on the dash and the truck downshifts and starts locking the TC in lower gears automatically, and it goes off around 270F. My interpretation is that Toyota thinks anything under 270F must be OK since there's no warning and the transmission behavior is normal at that point.

I've had my pan and TC up around 248-249 before climbing Monarch Pass in 2nd gear with my trailer attached. Temps were actually a couple degrees cooler in 2nd than in 3rd, probably because the A/T fluid is pumped by engine RPMs so it circulates faster. If you can't stay locked it's definitely better to use a lower gear when climbing and get the engine revving in the 4k+ range.

Yes they are the same app and I do have the enhanced diagnostics add-on for my 2018 LX. It has a ton of PID's but A/T Oil Temp 2 is not one of them. It has A/T oil temp 1 and 3. 3 appears to not be functioning correctly as it shows -40 when the truck is first started and its like 60* out. Eventually it does come up to higher temps but I dont know if they are right or not.

 

[skrypj]

That is awesome, I thought VFtuners could only do engine ECU, not transmission. Oh man I know what I want for my birthday next month!

Can you set the TC lock maps to only apply with in ECT PWR mode? (Or really is ECT PWR treated as a completely separate set of maps to program or is it layered over the base map?)

I'd have to look at a pre-2016 LC to know if its possible to set them separately. My 2018 tune has cold, warm, tow and 4lo. There is no specific sport mode settings and it appears to me my sport mode uses the same locking schedule as warm.

 

[linuxgod]

I'd have to look at a pre-2016 LC to know if its possible to set them separately. My 2018 tune has cold, warm, tow and 4lo. There is no specific sport mode settings and it appears to me my sport mode uses the same locking schedule as warm.

I'd be OK with sport mode (I think the S is actually "shift" mode) being the same map, but when I press the "ECT PWR" button I'd like that to act as a different map if possible. Basically I don't want to muck with the factory map in Eco/normal mode, at least right now. But if you have different maps for "warm" and "tow" that's probably the same thing I'm looking for?

 

[skrypj]

I'd be OK with sport mode (I think the S is actually "shift" mode) being the same map, but when I press the "ECT PWR" button I'd like that to act as a different map if possible. Basically I don't want to muck with the factory map in Eco/normal mode, at least right now. But if you have different maps for "warm" and "tow" that's probably the same thing I'm looking for?

Right but what I am saying are the tow maps don't appear to be active. At least not on my truck. I tow in S6 and also in Sport+. The tow mode maps do have some level of TC locking in 4th gear but that doesnt appear to happen.

 

[LX Cruiser]

To @linuxgod @dubyahard @chiplee and anyone else running a Lance 2185:

What is your loaded tongue weight? Thought I’d ask here since the Lance Owners’ forum requires registering to even browse topics.

I really like this camper, but it is notoriously tongue weight heavy. And it seems that they just keep getting heavier.

2024 specs:
Gross dry weight: 4860 lb
Hitch dry weight: 890 lb
That’s an 18.3% tongue weight.
Gross weight: 7900 lb

If we could travel with <6000 lb trailer weight with a 15% tongue weight, that wouldn’t bother me so much. I’m just not sure that’s possible with this camper. I know others on this forum pull heavier campers with attentive care given to potential issues.

 

[skrypj]

To @linuxgod @dubyahard @chiplee and anyone else running a Lance 2185:

What is your loaded tongue weight? Thought I’d ask here since the Lance Owners’ forum requires registering to even browse topics.

I really like this camper, but it is notoriously tongue weight heavy. And it seems that they just keep getting heavier.

2024 specs:
Gross dry weight: 4860 lb
Hitch dry weight: 890 lb
That’s an 18.3% tongue weight.
Gross weight: 7900 lb

If we could travel with <6000 lb trailer weight with a 15% tongue weight, that wouldn’t bother me so much. I’m just not sure that’s possible with this camper. I know others on this forum pull heavier campers with attentive care given to potential issues.

You could probably help the cause by swapping to Lithium batteries and running them in the rear of the trailer. The breaker/fuse panel seems to be under the stove so its already running wires 1/2 way down the length of the trailer. That would probably unload a couple hundred lbs from the tongue. Thats what I did on my trailer since mine seems to run a bit tongue heavy too and both the grey and black tanks are in front of the axles.

But, also, just based on the layout, it looks like you probably pack heavier/larger gear in the rear of the trailer in the bunk area further unloading the tongue. My trailer's cargo door is right in the very front so fire wood, bikes, chairs, tables, etc are all going almost entirely onto my tongue. This trailer looks like it would be the opposite.

 

[linuxgod]

To @linuxgod @dubyahard @chiplee and anyone else running a Lance 2185:

What is your loaded tongue weight? Thought I’d ask here since the Lance Owners’ forum requires registering to even browse topics.

I really like this camper, but it is notoriously tongue weight heavy. And it seems that they just keep getting heavier.

2024 specs:
Gross dry weight: 4860 lb
Hitch dry weight: 890 lb
That’s an 18.3% tongue weight.
Gross weight: 7900 lb

If we could travel with <6000 lb trailer weight with a 15% tongue weight, that wouldn’t bother me so much. I’m just not sure that’s possible with this camper. I know others on this forum pull heavier campers with attentive care given to potential issues.

Those 2024 specs are much more than the spec sheet says for mine. The GW is a LOT higher too, which is odd.

A couple years ago I came in at 920# TW, fully loaded, despite the spec sheet saying it was around 700#.

I've since moved my battery to Lithium and put it under the fridge. There are some other things you can do which will help (or at least change the distribution):

• You could put the spare underneath the rear of the trailer instead of the tongue. It would probably require some engineering/welding to mount it.
• Loading stuff in the storage area under the bunks will remove weight from the tongue. I typically put my cooler and firewood back there when we don't have bikes with us.
• Water will affect TW too. Fresh water sits in front of the axles, whereas gray I believe sits above them and black is behind.
• Try to shift other heavier stuff inside closer to the axle. i.e. if you have pots and pans in the forward dinette drawer maybe move those to the one closer to the axle.

 

[TeCKis300]

Also, I’m pretty sure what I am looking at is pan temps, not converter temps. I don’t believe OBDLink app has the PID for the converter temp for my 2018, just AT oil temp 1.

Is your thread saying you saw 266F torque converter temps but you were 230 pan temps while that happened? Because I’m pretty sure my pan temps have been up near 250. I was pulling into a 30-40 mph headwind at one point on my trip back in February and was running in 4th at 60 mph near WOT and my temps got up pretty high without even hitting a hill. Then I hit a big hill and I think that was when my AT oil temp 1 hit 249 or something.

There is an AT oil temp 3 in OBDLink but it’s screwy and scaling is def not right because it reads -40 when you start the truck.

Yes, the logic is triggering off of max torque converter temps. Which makes sense as the converter is ultimately drawing from the pan and T/C temps will only get hotter from there. I think max pan temps I've seen are in the 245 range after really really long pulls in summer. The torque converter will go into more aggressive lockup at 266F, where my pan is usually ~230F. At that point, the two temps match closely and creep up in lockstep as HP is being pushed through the tranny. Around 245F, I'll usually ease up a tad out of mechanical sympathy, but it seems to stabilize and not get much hotter than 250F. Especially now as I added a second tranny aux cooler to the factory aux cooler.

It seems that gearing is really important as the Tranny-ECU logic is built around ground speed. It's deriving ground speed not from the ABS/speedo, but from the output shaft speed of the transmission. With really large tires or over-gearing with 4.88s, it seems to skew the lockup logic more dramatically than it would seem.

 

[skrypj]

Yes, the logic is triggering off of max torque converter temps. Which makes sense as the converter is ultimately drawing from the pan and T/C temps will only get hotter from there. I think max pan temps I've seen are in the 245 range after really really long pulls in summer. The torque converter will go into more aggressive lockup at 266F, where my pan is usually ~230F. At that point, the two temps match closely and creep up in lockstep as HP is being pushed through the tranny. Around 245F, I'll usually ease up a tad out of mechanical sympathy, but it seems to stabilize and not get much hotter than 250F. Especially now as I added a second tranny aux cooler to the factory aux cooler.

It seems that gearing is really important as the Tranny-ECU logic is built around ground speed. It's deriving ground speed not from the ABS/speedo, but from the output shaft speed of the transmission. With really large tires or over-gearing with 4.88s, it seems to skew the lockup logic more dramatically than it would seem.

And see that's what I am a little worried about. If its only 60F outside I am already seeing close to 250F in the pan which means my TC is probably a lot higher. I dont think I have noticed it locking up but I was not logging the lockup PID at the time.

 

[TeCKis300]

And see that's what I am a little worried about. If its only 60F outside I am already seeing close to 250F in the pan which means my TC is probably a lot higher. I dont think I have noticed it locking up but I was not logging the lockup PID at the time.

What's your current mods and what tire size are you running? Might be worth putting in your sig?

250F does seem high but that might be true given the data your seeing. Question is why? IIRC, you might be running some big tires on factory gearing? This would appear to the ECUs as high load given the output and speeds it's seeing. Then the transmission ECU is deriving it's own ground speed. Both would tell the ECUs that it's seeing high loads, especially when towing, and hence it would tend to lockup less as it's trying to gain mechanical advantage. Generating more heat.

 

[skrypj]

What's your current mods and what tire size are you running? Might be worth putting in your sig?

250F does seem high but that might be true given the data your seeing. Question is why? IIRC, you might be running some big tires on factory gearing? This would appear to the ECUs as high load given the output and speeds it's seeing. Then the transmission ECU is deriving it's own ground speed. Both would tell the ECUs that it's seeing high loads, especially when towing, and hence it would tend to lockup less as it's trying to gain mechanical advantage. Generating more heat.

The truck is totally stock except for a Victory4x4 gas tank skid. I have 315/70's sitting in the garage but have not mounted them up yet.

 

[linuxgod]

Temps get hot when you are towing at elevation...