Putting the HT up/down when out of Park
01-20-16, 11:21 AM
#1
Lead Lap
Thread Starter
Putting the HT up/down when out of Park
I have been sitting on some information on how to disable the parking lock for the convertible roof because obviously it would be dangerous to allow the hard top to be opened or closed while driving. A few people here have expressed an interest in it, though.
The only way that I would be willing to share the info is if we could come up with some safe way to do it. I am opening this to discussion for those that are interested.
Obviously, the number one safety issue would be not to allow the top to move while in motion and not if the luggage tray cover isn't in position.
Even if we considered that most people would be smart enough not to try to open/close the top while driving, if that switch is enabled all the time, somebody bumping the switch would at least unlock the top which would make it unstable.
The only way I could think of to safely allow this feature is if we replaced the shift lock signal with the brake pedal signal.
The only desirable reason I can think of to disable this would be to allow it while stopped at a light, etc.. (though nothing is really stopping you from just putting the car in park while you do it.)
One last thought, since the button is not auto up/down, an issue would be that you could put it some intermediate position while your foot is on the brake, but then leave it there when you drive off. I guess technically you could probably do that now by starting the process while in park.
Just looking for some thoughts on this and whether it is really something worth doing.
The only way that I would be willing to share the info is if we could come up with some safe way to do it. I am opening this to discussion for those that are interested.
Obviously, the number one safety issue would be not to allow the top to move while in motion and not if the luggage tray cover isn't in position.
Even if we considered that most people would be smart enough not to try to open/close the top while driving, if that switch is enabled all the time, somebody bumping the switch would at least unlock the top which would make it unstable.
The only way I could think of to safely allow this feature is if we replaced the shift lock signal with the brake pedal signal.
The only desirable reason I can think of to disable this would be to allow it while stopped at a light, etc.. (though nothing is really stopping you from just putting the car in park while you do it.)
One last thought, since the button is not auto up/down, an issue would be that you could put it some intermediate position while your foot is on the brake, but then leave it there when you drive off. I guess technically you could probably do that now by starting the process while in park.
Just looking for some thoughts on this and whether it is really something worth doing.
01-20-16, 12:21 PM
#2
If I remembered correctly, you can still operate the top outside of D as long as the car is not moving or rolling. I may have tried to put it in N and foot off the brake pedal to have the top operates, as long as the car is not rolling. I really don't remember correctly now.
01-20-16, 02:19 PM
#4
That is my recollection also, although with two feet of snow coming this way, I haven't tested it lately. I don't think that you have to be in PARK, just that you can't be moving. If you start moving, the top will cease opening or closing as soon as you exceed any appreciable speed.
While I certainly understand while Lexus has the lockout, as an adult I'm responsible for my actions, so if I were to decide to try putting the top down at Autobahn speeds, that's on me! Plus any accidental bumping of the switch would be noticed immediately and could be dealt with.
So I say, go for it! It would be good to be able to put the top up in rush hour stop/go when it starts raining without having to pull over or get honked at.
While I certainly understand while Lexus has the lockout, as an adult I'm responsible for my actions, so if I were to decide to try putting the top down at Autobahn speeds, that's on me! Plus any accidental bumping of the switch would be noticed immediately and could be dealt with.
So I say, go for it! It would be good to be able to put the top up in rush hour stop/go when it starts raining without having to pull over or get honked at.
01-20-16, 03:22 PM
#6
You can operate the top up to 5mph in motion. After this limit the top will freeze in whatever position it is at that point and give you an error chime and a flashing light on the button. For most, it will roll back down passively due to its own weight either into the trunk or in the closed (hard top position). Package tray will remain in frozen state until you decrease your speed and press the button again to which it will pick up the cycle in the place it locked you out. When stopped at a light or in traffic, I drop the top all the time. Usually it takes only 28 seconds from top up to top down and vice versa. Usually a red light or slow rolling traffic is long enough to complete the cycle. But if the light is short or traffic moves, you can theoretically drive up to 5mph and the top cycle will continue before the lock out kicks in. I do it all the time. Also, you DON't have to be in Park. Drive, Reverse, Neutral all work to allow the top to cycle. I also read that it's never a good idea to try to cycle the top without the car actually running. If you're only on ACC and cycle the top and battery craps out mid cycle, you might cause sensor errors with the TOP ECU.
PS, I recommend not changing this safety 5mph feature. Just my opinion. It's built to keep the top functional. Think about it. If you risk going faster or catch a burst of air in the top while in motion. Boom, motors or gears get stripped... think about how much Lexus will charge you. Those motors and gears are fairly affordable, but the labor is outrageous. Something to consider. Some may say, "well i'm not going to use it at high speed," but you never know. Acccidents can happen. (Not to point fingers but there was a member who mentioned he accidentally shifted into Reverse while cruising highway speeds- found out that his rearview camera will kick on but also the car won't shift into Reverse. An accident all the same, but it happened). A kid or mischievous passenger might hit the button while on the highway. Think worst case scenario and how this simple lockout feature could save you thousands (and possibly save the life of the person following you if the top came flying off your SC).
PS, I recommend not changing this safety 5mph feature. Just my opinion. It's built to keep the top functional. Think about it. If you risk going faster or catch a burst of air in the top while in motion. Boom, motors or gears get stripped... think about how much Lexus will charge you. Those motors and gears are fairly affordable, but the labor is outrageous. Something to consider. Some may say, "well i'm not going to use it at high speed," but you never know. Acccidents can happen. (Not to point fingers but there was a member who mentioned he accidentally shifted into Reverse while cruising highway speeds- found out that his rearview camera will kick on but also the car won't shift into Reverse. An accident all the same, but it happened). A kid or mischievous passenger might hit the button while on the highway. Think worst case scenario and how this simple lockout feature could save you thousands (and possibly save the life of the person following you if the top came flying off your SC).
Last edited by ShawnOk; 01-20-16 at 03:36 PM.
01-20-16, 03:54 PM
#7
You can operate the top up to 5mph in motion. After this limit the top will freeze in whatever position it is at that point and give you an error chime and a flashing light on the button. For most, it will roll back down passively due to its own weight either into the trunk or in the closed (hard top position). Package tray will remain in frozen state until you decrease your speed and press the button again to which it will pick up the cycle in the place it locked you out. When stopped at a light or in traffic, I drop the top all the time. Usually it takes only 28 seconds from top up to top down and vice versa. Usually a red light or slow rolling traffic is long enough to complete the cycle. But if the light is short or traffic moves, you can theoretically drive up to 5mph and the top cycle will continue before the lock out kicks in. I do it all the time. Also, you DON't have to be in Park. Drive, Reverse, Neutral all work to allow the top to cycle. I also read that it's never a good idea to try to cycle the top without the car actually running. If you're only on ACC and cycle the top and battery craps out mid cycle, you might cause sensor errors with the TOP ECU.
PS, I recommend not changing this safety 5mph feature. Just my opinion. It's built to keep the top functional. Think about it. If you risk going faster or catch a burst of air in the top while in motion. Boom, motors or gears get stripped... think about how much Lexus will charge you. Those motors and gears are fairly affordable, but the labor is outrageous. Something to consider. Some may say, "well i'm not going to use it at high speed," but you never know. Acccidents can happen. (Not to point fingers but there was a member who mentioned he accidentally shifted into Reverse while cruising highway speeds- found out that his rearview camera will kick on but also the car won't shift into Reverse. An accident all the same, but it happened). A kid or mischievous passenger might hit the button while on the highway. Think worst case scenario and how this simple lockout feature could save you thousands (and possibly save the life of the person following you if the top came flying off your SC).
PS, I recommend not changing this safety 5mph feature. Just my opinion. It's built to keep the top functional. Think about it. If you risk going faster or catch a burst of air in the top while in motion. Boom, motors or gears get stripped... think about how much Lexus will charge you. Those motors and gears are fairly affordable, but the labor is outrageous. Something to consider. Some may say, "well i'm not going to use it at high speed," but you never know. Acccidents can happen. (Not to point fingers but there was a member who mentioned he accidentally shifted into Reverse while cruising highway speeds- found out that his rearview camera will kick on but also the car won't shift into Reverse. An accident all the same, but it happened). A kid or mischievous passenger might hit the button while on the highway. Think worst case scenario and how this simple lockout feature could save you thousands (and possibly save the life of the person following you if the top came flying off your SC).
That's why I've never done it in the BMW even though it says you can. I don't think I've exceeded 10 mph and felt that was pushing it. It's like a huge wind sail when it's going up or down.
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01-20-16, 04:44 PM
#8
.....
(oh, yeah. Never mind).
01-20-16, 07:59 PM
#9
Lead Lap
Thread Starter
Awesome info, Shawn. That's pretty much already doing it the way I would think is safe.
It sounds like no mod is needed.
Johnny, I had a Dodge Intrepid many years ago that the transmission was starting to go out in. It had trouble shifting out of 1st gear. I can't exactly remember why I tried it, but I threw the car in reverse while cruising (only about 15-20 though) and no traffic around me. The car wasn't so smart though. Felt like I hit a brick wall and then it stalled.
It sounds like no mod is needed.
Johnny, I had a Dodge Intrepid many years ago that the transmission was starting to go out in. It had trouble shifting out of 1st gear. I can't exactly remember why I tried it, but I threw the car in reverse while cruising (only about 15-20 though) and no traffic around me. The car wasn't so smart though. Felt like I hit a brick wall and then it stalled.
01-20-16, 08:15 PM
#10
No problem. I recently watched the newest Bond installment... and not to give away any spoilers... but there's a scene in the extreme car chase where he throws the top off a very exclusive roadster (heavily modified by Q)... to parachute away from his enemies. In this extreme case, having the top-lockout disabled would be beneficial. But until you've received your Licence to Kill.... I'd keep it under 5mph.
Last edited by ShawnOk; 01-20-16 at 09:49 PM.
01-20-16, 10:28 PM
#12
Retro something that I might be interested in & being along the same lines. I haven't done the quarter window mod,but there is a procedure that allows you to let the quarter windows up with the top down, but you get the warning buzzer / flashing light. It's been along time since I've done it, so don't remember the sequence off the top of my head,but I would like to be able to roll the quarters up & not have the warning buzzer / light. I'm pretty sure someone will chime in tomorrow with the procedure, before I get back online & hopefully it will shed some light on this matter. There may be a way to disarm the warning buzzer using the OBD scanner/tool, but not sure. I've been putting off doing the mod, but may go ahead & jump into it, but have come to realize with the top down & the quarters up, it's a lot less wind & much quieter
01-21-16, 01:10 AM
#13
Lead Lap
Thread Starter
Retro something that I might be interested in & being along the same lines. I haven't done the quarter window mod,but there is a procedure that allows you to let the quarter windows up with the top down, but you get the warning buzzer / flashing light. It's been along time since I've done it, so don't remember the sequence off the top of my head,but I would like to be able to roll the quarters up & not have the warning buzzer / light. I'm pretty sure someone will chime in tomorrow with the procedure, before I get back online & hopefully it will shed some light on this matter. There may be a way to disarm the warning buzzer using the OBD scanner/tool, but not sure. I've been putting off doing the mod, but may go ahead & jump into it, but have come to realize with the top down & the quarters up, it's a lot less wind & much quieter
I am not aware of any procedure to stop the buzzer. There is an "enable" line coming from the hart top ECU. This signal is one end of the open/close switches (ground.) The ECU simply opens this line and that disables the switches. The beeping appears to be controlled in the A/C controls itself whenever the buttons are pressed with the enable signal missing.
The bypass (needs to be tested) would have involved providing the 12V or ground to the enable line.
The ECU, however, does all the logic to determine whether the switches can be enabled or not. So it is possible that it would just ignore the bypassed switches (meaning it may not be THAT simple.)
Anyway, my point is that there probably isn't a way to disable the buzzer without modding the internals of the A/C control unit.
The quarter window mod is not especially complicated and would result in a more desirable result, anyway. The quarter window mod simply connects between the motors and the ECU. It disconnects the ECU and controls the motors directly using something called a roll up/down module which is available just about anywhere.
The hardest part of the install (besides removing panels to get to stuff) would be routing wiring up to the dash to install the switches. I will be putting together a mod to make this wireless and controllable from the homelink unit once the weather is a little better.
Last edited by Retroplay; 01-21-16 at 01:49 AM.
01-21-16, 01:28 AM
#14
Lead Lap
Thread Starter
The "C" terminal is the 14 pin connector on the backside of the A/C controls. Pin 5 is the SWE (Switch Enable) signal. If the ECU opens this line, then the switches will do nothing. SWE is connected to ground when all the conditions are met for safe HT operation. A bypass would be to jumper pin 5 to ground and the switches should always be enabled.
Whether the ECU will react or just report an error, however, needs some testing. If we get some more agreeable weather soon, I will confirm. If the ECU will not react after bypass, then the signals for the speed/parking switch are coming over the BEAN bus. To bypass that would require hijacking the BEAN bus to trick the HT ECU into thinking the conditions are valid.
That's probably the extent of the information I would give for this mod. if someone else wants to pursue it, this is a good start. Based on Shawn's description of the operation, I am already satisfied myself with how it works currently, except that I don't like how it will stay in an intermediate stage of open/close.
I do have a question for those with more experience operating the HT: Is there some sequence which makes it automatic? Meaning, do something and then the top will open or close without interruption even if you stop pressing the button? I imagine not because it is probably considered a safety feature allowing you to stop the movement if somebody's head is in the way for example.
Last edited by Retroplay; 01-21-16 at 01:53 AM.
01-21-16, 05:13 AM
#15
Agreed, but I fear the top frozen in the mid-open position just because I hit 6 MPH in stop/go traffic. The top already seems like a Rube Goldberg machine so I don't like the idea of the process being interrupted.