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Any aftermarket reprogram of transmission?

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Old 04-30-14, 10:26 PM   #1
satz
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Default Any aftermarket reprogram of transmission?

hi all

I really like many aspects of my AWD 07 RX350, except for its transmission.

Most of the time it operates as well as one can expect a 5-speed auto to work. However, the most annoying aspect is how long it sometimes takes to kickdown a gear.

eg. when crawling along in traffic and I see a gap and floor the accelerator, it take seemingly ages to kickdown and usually results in me missing the gap. This also happens when I press the accelerator a little more gently.

Also, when overtaking on a highway. Seems like it sometimes hesitates to kickdown

I think manually shifting in the sports mode does cure this, but was wondering whether there's some permanent fix in the fully auto mode.
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Old 05-01-14, 08:49 AM   #2
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Default transmission lag

I was about to post this exact same issue. It shifts very smooth under normal driving but when power is needed to get out of a jam, its not therethere. The worst is at metered onramp where you have to get from 0-65mph ASAP or get rear ended. The RX sux at that but once up to speed it cruises beautifully. I wish we had a auto sport mode when needed. Back in the day on my Chevelle SS, I put in a B&M Shift Kit and it made a world of difference like it was a different car.
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Old 05-01-14, 08:54 AM   #3
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Default transmission lag

I was about to post this exact same issue. It shifts very smooth under normal driving but when power is needed to get out of a jam, its not therethere. The worst is at metered onramp where you have to get from 0-65mph ASAP or get rear ended. The RX sux at that but once up to speed it cruises beautifully. I wish we had a auto sport mode when needed. Back in the day on my Chevelle SS, I put in a B&M Shift Kit and it made a world of difference like it was a different car.
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Old 05-01-14, 09:58 AM   #4
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The kick-down is a bit of a delayed action on mine too. It does take off like a jet fighter when it comes in, almost like trying to make up for lost time, but that doesn't help for that split second you really need it. Hope the guys will come in here and share some info.
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Old 05-01-14, 03:39 PM   #5
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I believe I heard someone talking about disconnecting the battery for 30 minutes to reset the ECM. Your car will then re-"learn" your driving style. There are a lot of conservative women driving these things, not knocking anyone but I've noticed they are not very fast or aggressive drivers. Perhaps it learned from them!

I don't know the extent or mechanism for this "learning" though. But I would think it would have to center around shifting.
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Old 05-02-14, 07:24 AM   #6
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The other thing I thought today is that what you guys are describing sounds a lot like when you have the Snow ECT enabled.
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Old 05-02-14, 07:48 AM   #7
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This is typical of cars from this era, DBW Lag.

I believe Apexi makes an Accel controller compatible with these cars.
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Old 05-02-14, 07:52 AM   #8
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I have no lag whatsoever in my '07.
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Old 05-02-14, 10:57 PM   #9
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I also have no lag when downshifting, takes off like a rocket. Ever had the throttle body and MAP sensor cleaned ? Tranny fluid been changed lately ? Using premium fuel ?

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1998 SC300 DWP/beige 147,000 miles
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Old 05-02-14, 11:34 PM   #10
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I have an 04 RX330 AWD, but even in that, when you put the pedal to the floor it downshifts immediately to provide more power. That being said, I have driven many other Toyota products with the 3.5L 2gr engine in it with a 5 or 6 speed auto.

With the 3.5 2gr paired with the 5 speed, every now and then it seems to hold whatever gear it is in when you floor it, instead of downshifting a gear like it should. The 6 speed seems to rectify this problem, as I have yet to experience the same phenomenon with a 2gr with a 6 speed.

It is possible that what you are experiencing is a flaw in the programming of the transmission. I would disconnect the battery for 30mins (at least) to let the ECU reset, and then reconnect the battery. In the first 30 or so miles, the ECU with relearn your driving style, and try to optimize to it. This may or may not help the problem, but it is worth trying.

Note: When you disconnect the battery, you will likely lose memory seat settings and stereo settings. You will also need to reinitialize the windows and moonroof. Search the forum for details. Also, do not be alarmed if you have an unusually low engine idle when you reconnect the battery and start the engine. This is normal. When the battery has been disconnected for a substantial period of time, the ECU must also relearn the engine idle speed. If the engine idle is unusually low, drive the car for approximately 1 mile, and it will relearn the engine idle speed.
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Old 05-05-14, 01:37 AM   #11
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I did a particularly winding and climbing route yesterday and my RX350 tends to continue in the present gear for far too long and you must activate the kickdown feature, before it feels comfortable on the gradient. Is that because torque is developed in this particular engine at quite high revs?

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Old 05-05-14, 11:47 AM   #12
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Default transmission lag

Mine takes off like a rocket, its the ultra smooth shifting that feels like a clutch slipping on a manual tranny. And the kick downshift works intermittently. When it kicks in, its fast but more times than not there's a delay lag that prevents you from passing resulting in missed opportunities.
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Old 05-06-14, 01:20 AM   #13
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Quote:
Originally Posted by Gordonrx View Post
Mine takes off like a rocket, its the ultra smooth shifting that feels like a clutch slipping on a manual tranny. And the kick downshift works intermittently. When it kicks in, its fast but more times than not there's a delay lag that prevents you from passing resulting in missed opportunities.
You're last two sentences are interesting, but needs a bit more explanation. Are you saying it should be like that? If it is the case, it can lay a few ghosts to rest.
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Old 05-06-14, 01:20 AM
 
 
 
 
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