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yup, it's 100% throttle opening before the switch. There might be load or timing differences, but my test proves the throttle position isn't affected by a transmission kick down switch.
Now I'm confused.... If it's 100% throttle opening before the switch, what the heck is this switch doing?
Now I'm confused.... If it's 100% throttle opening before the switch, what the heck is this switch doing?
It's doing what it's named for: kicks down the transmission to a lower gear. In my test, at 60mph it's the difference between dropping to 4th or 3rd gear.
It's actually an old tech feature. End result is that the car goes really fast, or it believes you really meant it and engages ludicrous speed.
It's doing what it's named for: kicks down the transmission to a lower gear. In my test, at 60mph it's the difference between dropping to 4th or 3rd gear.
It's actually an old tech feature. End result is that the car goes really fast, or it believes you really meant it and engages ludicrous speed.
What OBD2 scanner are you using? I connected my KIWI4 using OBD Fusion app and here's what I got. This is just with the IGN in the ON position, engine off (not sure if it makes a difference)
I don't think the throttle plate is moving with the engine off, but I'm not getting 100% pedal output.
What OBD2 scanner are you using? I connected my KIWI4 using OBD Fusion app and here's what I got. This is just with the IGN in the ON position, engine off (not sure if it makes a difference)
I don't think the throttle plate is moving with the engine off, but I'm not getting 100% pedal output.
pedal on the first stop:
Pedal all the way down
I have an OBDlink LX dongle and am using the OBDLink app. Paid the $10 for Lexus specific diags, so it connects to more networks than just the generic OBD2 protocol. I just set it up to monitor the PIDs related to throttle and accelerator position. Was pleasantly surprised it had the kick down switch flag as an available parameter.
Did a quick data capture and created this chart from it showing accelerator position, throttle plate position, and kickdown switch position. From all indications, there's no difference in throttle position when you hit the kickdown switch. I did this on two separate trials, and the results are interesting to say the least.
Last edited by lobuxracer; Mar 25, 2020 at 06:52 PM.
It's doing what it's named for: kicks down the transmission to a lower gear. In my test, at 60mph it's the difference between dropping to 4th or 3rd gear.
It's actually an old tech feature. End result is that the car goes really fast, or it believes you really meant it and engages ludicrous speed.
Yea Lexus has been employing this for a while, had it on the SC400. Engages hard downshifting, no impact on throttle opening. Think it's mentioned in the manual
Thanks all for the technical info. Now, if I may ask a non-technical question where I hope to understand the answer.
If one shortens the springs as has been illustrated, does the transmission shift to a lower gear at the same pedal location as compared to stock length springs?
Thanks all for the technical info. Now, if I may ask a non-technical question where I hope to understand the answer.
If one shortens the springs as has been illustrated, does the transmission shift to a lower gear at the same pedal location as compared to stock length springs?
Thanks
Cutting those springs only affects the *effort* needed to push the kickdown button. The general complaint is that it feels like you've floored the pedal and engaging that button requires extra effort. The spring mod makes it a bit easier to floor it and hit the kickdown button at the same time.
Cutting those springs only affects the *effort* needed to push the kickdown button. The general complaint is that it feels like you've floored the pedal and engaging that button requires extra effort. The spring mod makes it a bit easier to floor it and hit the kickdown button at the same time.
Exactly correct.
I just realized I forgot to mention, I was in Sport mode (not Sport+) and TVD in slalom (my standard every time I get in the car mode). I am thinking I need to replicate this with my IS F as it is on the original '08 engine management software - I have refused the "upgrade" to let the brake override the throttle every time I have been to Lexus, and I always will. I could flash it myself with my Techstream subscription, but I don't want to invoke this feature if I can avoid it.
Cutting those springs only affects the *effort* needed to push the kickdown button. The general complaint is that it feels like you've floored the pedal and engaging that button requires extra effort. The spring mod makes it a bit easier to floor it and hit the kickdown button at the same time.
I have refused the "upgrade" to let the brake override the throttle every time I have been to Lexus, and I always will. I could flash it myself with my Techstream subscription, but I don't want to invoke this feature if I can avoid it.
Yep, me too. I never applied the; change to my ISF, but I now have the "feature" on my LC and I absolutely HATE it
Sort of replying to a dead thread, but in the graph by lobux in the #35, is the purple line showing full throttle (I mean 100% throttle, not the position of the gas pedal)? Or is it like 80% throttle or something
on my LC and I absolutely HATE it
