Power Mode Switch Installed, Very Pleased

[It's Just Eric]

Well, your car being a 96...doesnt actually have a light for power mode...so mabey, when you arent looking, Ill just ground pin a4 and see if you notice something diffrent on your ride home

[Nomake Wan]

Okay guys, I have run some tests on the highway on my way back from work and I can confirm that POWER mode does, in fact, prevent the torque converter from locking up. I also discovered why I never noticed it on long-distance cruises.

If you turn on the cruise control, the cruise control module shuts POWER mode off. Once it's off, the torque converter locks up. As soon as you turn cruise off (or hit the brake, or pull the handle), the torque converter unlocks (since POWER mode came back on).

So I still don't need a switch. I use cruise control on long-distance cruises, which locks the torque converter. If I don't need cruise control, chances are it's not long-distance, so therefore I'd like to have my power.

[b3lha]

Originally Posted by Nomake Wan

If you turn on the cruise control, the cruise control module shuts POWER mode off. Once it's off, the torque converter locks up. As soon as you turn cruise off (or hit the brake, or pull the handle), the torque converter unlocks (since POWER mode came back on).

So I still don't need a switch. I use cruise control on long-distance cruises, which locks the torque converter. If I don't need cruise control, chances are it's not long-distance, so therefore I'd like to have my power.

Good thinking! I think the cruise control also uses a different shift map in the TCU.

FYI the manual button also turns power mode off.

[svxistentialist]

Originally Posted by Nomake Wan

Okay guys, I have run some tests on the highway on my way back from work and I can confirm that POWER mode does, in fact, prevent the torque converter from locking up. I also discovered why I never noticed it on long-distance cruises.

If you turn on the cruise control, the cruise control module shuts POWER mode off. Once it's off, the torque converter locks up. As soon as you turn cruise off (or hit the brake, or pull the handle), the torque converter unlocks (since POWER mode came back on).

So I still don't need a switch. I use cruise control on long-distance cruises, which locks the torque converter. If I don't need cruise control, chances are it's not long-distance, so therefore I'd like to have my power.

That's excellent.

Do all US cars have cruise, or just the top of the range Lsl models?

It has already been mentioned that Power mode is not any great benefit at cruising or steady speed anyway, only for hammering-on back roads style driving or for overtaking.

If you have cruise, you can engage lock-up, switch off cruise and you are back to Power mode.

BTW, if any of you guys with the Power mode mod newly fitted do not have cruise, you can still make your car lock-up on a long drive; switch on Manual, y'know, the MANU light on the dash? While this mode is engaged Power mode is denied at the gearbox. Your tranny will lock up no bother. Turn off MANU and you are back in Power mode.

Joe

[svxistentialist]

Phil beat me to it

[Nomake Wan]

Negative negative negative, guys. Turning on manual mode does not turn POWER mode off. I can have both on at the same time. There's no real point to doing so, but I can do it.



However, once the manual map is enabled (by putting the shifter in 3 or 2) then yes, Power Mode goes away. But it will remain on in drive, which is what you're going to want on long cruises anyway.

However, I will at this point note that all USDM SVXs have Cruise Control, regardless of trim. So no worries there.

[Myxalplyx]

So how long would something like this take for a seasoned professional like Young Tom to install?

I have an idea for this beyond the SVX.

[svxistentialist]

Originally Posted by b3lha

Good thinking! I think the cruise control also uses a different shift map in the TCU.

Phil, I have disagreed with this view before, with Harvey if I remember correctly.

From reading all the information available in the WSMs and in different articles published it is my opinion that there are only TWO different shift reference maps in the TCU software, Power map and Normal map. Other driving "modes" that we know about use variants of the two primary shift maps.

This is how I see the differences:

1)Normal Shift Map:
This map is tuned for economy and quietness. Shifts happen at low revs to take advantage of the high torque engine and to get the car as soon as possible into D4 range for quiet and economical low revs driving.

Lock-up is available, for economy reasons.

Kick down is available, but reluctantly; the map is tuned to hold higher gears, even for overtaking, unless it sees very fast movement from the TPS or WOT.

2)Power Shift Map:
Power shift map is tuned for overtaking and hill climbing.

It holds lower gears for longer.

It will kick-down more readily for less throttle movement.

Lock-up of the torque convertor is not available.

Power Mode on-demand:
This mode does actually use a reference map to measure variables such as road speed, range engaged and throttle opening speed, but is not a shift map per se.

It uses the data to toggle the shift maps between Normal and Power.

Standard running mode will be with the economy tuned Normal shift patterns engaged.

At lower speeds and higher throttle demands the higher-revving and torque convertor aided Power shift map will be engaged.

Once fast throttle change or WOT condition has ended, i.e. steady throttle is used, the gearbox drops back from Power to Normal inside 3 seconds.

Economy Mode:
This mode is a variant of the Normal shift map. It switches off Power-on-demand and does not allow any access to the Power shift map.

Driving with ECON engaged will always use the Normal shift map, which is economy tuned.

Manual Mode:
This mode is a variant of the Normal shift map also. It uses the same shift parameters as the economy tuned Normal map.

The only difference is it locks out 1 Range and will always start in 2 Range. This is to avoid wheelspin in muddy or slippery conditions. Manual applies to 2, 3 and D.

Cruise Control:
This mode uses the Normal shift map so that the lock-up feature is available while cruise is engaged. For this reason it can't use the Power map.

It is erroneous to be thinking of shift maps for Cruise anyway, as it is a steady speed control device and will not use shifts. However, for the sake of completeness, while cruise is engaged the TCU is operating the Normal map so that Lock-up is available.

----------------------------

As I said, this is my opinion, but it's based on reading anything I could find available in the technical manuals. If anybody thinks there are other factors at play, other shift maps, please fell free to contradict.

But do explain why, and where the information came from.

Joe

[svxistentialist]

Originally Posted by Nomake Wan

Negative negative negative, guys. Turning on manual mode does not turn POWER mode off.


However, once the manual map is enabled (by putting the shifter in 3 or 2) then yes, Power Mode goes away. But it will remain on in drive, which is what you're going to want on long cruises anyway.

However, I will at this point note that all USDM SVXs have Cruise Control, regardless of trim. So no worries there.

No no Nomake.

You are confusing the lights on the dash with what the gearbox is doing.

Don't forget that in your US car, in un-modded condition, there is no situation where you have MANU lit up on the dash that the Power light will come on while driving. This is because manual mode is designed to cope with slippery conditions. It was not envisaged that Power shift map would be needed in slippery conditions.

I think what you have in your case is the Power light is lit when in D4 mode [because you have grounded the pin], but MANU still over-rides what the box is doing.

If I'm wrong [I've been wrong before, so I could be ] then it means Manual denies the use of 1 Range in any conditions, restricts the shift map to Normal only in 2 Range and 3 Range, then returns to Power-on-demand for D4.

Is there any way you can determine by driving that with MANU engaged you are actually in Power mode once you get to 4? That will settle the matter.

Joe

[Nomake Wan]

Originally Posted by Myxalplyx

So how long would something like this take for a seasoned professional like Young Tom to install?

I have an idea for this beyond the SVX.

Considering it took me all of fifteen minutes to wire up the first time (getting the wire to stay in the harness took the most time; this was solved the second time around by using an actual TCU pin instead), it should take someone who knows what they're doing all of maybe five minutes, if that. If installing a switch it'll take as long as it takes to put a switch in. It's really that easy.

svxistentialist, it was said over on LegacyCentral that activating the Cruise Control module will cause the 4th gear shift to come sooner than usual. That's the only thing I've heard about it altering.

http://bbs.legacycentral.org/viewtopic.php?t=1468

[svxistentialist]

That makes interesting reading Nomake, thank you.

If the Legacy fellows are right, then maybe cruise does actually have its own separate shift map.

However, this directly conflicts with at least two technical manuals I have that state the gearbox operates from two maps.

Maybe when cruise is activated and rapid acceleration is required it allows access to the Power shiftmap for safety reasons? Would the Power light come on when accelerating out of cruise mode? Has anybody noticed?

Joe

[Nomake Wan]

Originally Posted by svxistentialist

That makes interesting reading Nomake, thank you.

If the Legacy fellows are right, then maybe cruise does actually have its own separate shift map.

However, this directly conflicts with at least two technical manuals I have that state the gearbox operates from two maps.

Maybe when cruise is activated and rapid acceleration is required it allows access to the Power shiftmap for safety reasons? Would the Power light come on when accelerating out of cruise mode? Has anybody noticed?

Joe

I have no clue what it does, actually. I mean, all he says to do is have the cruise control module on, not activated. When it's just on (on my SVX) but not operating, the car runs like normal (i.e. in Power Mode). I haven't noticed any changes. But as soon as you tell it to operate, it kills Power Mode and uses the economy map. Since nothing happens with the module merely on, I wonder how it can affect how soon the fourth gear shift happens. It appears, from that guy's post, that it will allow for a fourth gear shift above 4000 RPMs as long as you aren't at WOT. Sadly I no longer own my Legacy, and never had the space to experiment with his advice. I cannot confirm the cruise control's effect on that car's shifts. However, if we think of this a different way, it will make sense. Let me elaborate.

The transmission has two full shift maps; Economy and Power. But what happens when you switch on Manual? That's not a shift map. It most definitely alters the operation of the transmission, but it's not a map. So since we already have proof of the existence of a function built into the transmission that is not a map but alters its operation, it is conceiveable that Cruise would be able to alter its operation as well.

To test your other pondering, I would have to disable my mod and hop onto the freeway. Though, thinking it through logically, I would assume that Power Mode would not come on. Here's why.

Under normal operating conditions, mashing the gas will inform the computer that you want Power Mode, and it will come on. If you mash the gas in Cruise, the computer has locked out that selection and therefore the input for "quickness" reaches the ECU and is ignored. Since it was ignored, turning off cruise leaves the ECU merely with the fact that you're at WOT; not that you mashed the gas. Therefore, Power Mode will not come on.

As for your question about Power, Manual and 4th... it wouldn't matter. The only way to get to 4th gear in Manual would be to hit redline in 3rd... and once you've shifted into 4th Power Mode makes no difference (all you're doing is putting torque into the transmission; there's nothing to regulate). If you put the shifter into D to access 4th, you therefore disable Manual and enable Power, killing the experiment.

It's not as much that Power is enabled for 4th gear... it's that Manual is disabled for 4th gear. As has also been documented on LegacyCentral, turning the manual switch on in 'D' will display the indicator but will make no changes whatsoever to the operation of the transmission. Similarly, placing the shifter in '1' with the manual switch on will make no changes to the operation of the transmission (Manual locks out 1, but you told the transmission you want to use 1). Placing the shifter in '2' or '3' will use the Manual function, starting in the gear you selected and shifting differently. So only in '2' and '3' is there any meaning to using Manual.

Sound okay?

[b3lha]

Originally Posted by Nomake Wan

Negative negative negative, guys. Turning on manual mode does not turn POWER mode off. I can have both on at the same time. There's no real point to doing so, but I can do it.

Originally Posted by svxistentialist

You are confusing the lights on the dash with what the gearbox is doing.
Don't forget that in your US car, in un-modded condition, there is no situation where you have MANU lit up on the dash that the Power light will come on while driving. This is because manual mode is designed to cope with slippery conditions. It was not envisaged that Power shift map would be needed in slippery conditions.

I have just checked the TCU program and can give a definitive answer.

On a JDM TCU, the logic goes like this:

1. If cruise is on, set normal mode and goto 5
2. If manual switch is on, set normal mode and goto 5
3. If power switch is on, set power mode and goto 5
4. Decide whether to use normal or power based on speed and throttle.
5. Exit

On a USDM, the logic goes like this:

1. If cruise is on, set normal mode and goto 5
2. If manual switch is on and the stick is in 1,2,3, set normal mode and goto 5
3. If power switch is on, set power mode and goto 5
4. Decide whether to use normal or power based on speed and throttle.
5. Exit

In other words, on a JDM car, the manual switch overrides the power switch in every stick position. On a USDM car, it only overrides it in postions 1 2 and 3. I am surprised to see the manual and power mode on at the same time. If you have the car in D with the manual switch on and the power switch off, can you engage power by stomping the gas? It looks possible on a USDM car, but not on a JDM car.

[svxistentialist]

Originally Posted by svxistentialist

If I'm wrong [I've been wrong before, so I could be ] then it means Manual denies the use of 1 Range in any conditions, restricts the shift map to Normal only in 2 Range and 3 Range, then returns to Power-on-demand for D4.
Joe

Originally Posted by b3lha

I have just checked the TCU program and can give a definitive answer.
.......
In other words, on a JDM car, the manual switch overrides the power switch in every stick position. On a USDM car, it only overrides it in postions 1 2 and 3. I am surprised to see the manual and power mode on at the same time. If you have the car in D with the manual switch on and the power switch off, can you engage power by stomping the gas? It looks possible on a USDM car, but not on a JDM car.

Phil, thanks, this is very interesting, and we are getting closer to the truth. I had thought that Nomake's situation with both lights on only related to the circuits that lit the respective lamps, that Manual mode still denied Power map application in 4 Range.

From what you say it looks possible or maybe probable that in the US cars, even with Manual engaged, as soon as 4 Range is achieved the gearbox reverts to Power-on-demand.

For Nomake to check this he would need to turn off permanent Power mode, turn on MANU, drive at slow speed [40ish] in 4 Range and floor the throttle to see if the Power light comes on.

Joe

[Nomake Wan]

I tested that with my Legacy (without knowing it... I just did it because I wanted to go fast, haha) and it worked. I assume the SVX would be the same.