NGG

Have an 07 IS350. Notice when gently braking while in 6th gear and trans shifts sequentially to 5th then fourth it feels that more braking force is being applied when in fourth. Notice this also when just taking foot off the gas...appears as brakes are being automatically applied. Is this brake assist comming into play?. Not sure I like it in gentle decelleration.

Also sometimes when downshifted to fiurth, trans seems to stay in fourth longer than it should after gas applied.

Anyone have explanations for this. Thanks,

NGG

Any explanations. Thanks.

iSuxeL

iTrader: (21)

The tranny/ecu is very smart it shifts where it thinks is the best rpm. Also the problem youre concerned about seems perfectly normal IMO.

crispy136

This is normal operation when the transmission is left in D. If you also have "Power" selected on the ECT the transmission will change down more often and sometimes drop stright to 3rd. It can be disabled by placing the transmission lever in S. This not only enables the paddle shifts but disables the downshifts on braking (called AI by Lexus). As long as the indicator is in 6, the transmission operates automatically, but won't downshift under braking.

NGG

Thanks for the responses. However they tend to explain the shifting of the transmission as opposed to my real question re the apparent auto application of the brakes while slowing down, most noticable in fourth gear.

To others who may have an answer please refer to my post (first in this thread) for a more detailed situation description.

All responses appreciated. Thanks.

crispy136

In the case of my car the brakes are definitely not applied automatically, the only deceleration is caused by the lower gear ratio selected. The only automatic braking I have encountered was in an IS250 loan car, when the radar cruise control applied the brakes when coming up to a slower moving vehicle. Of course it beeped its head off so it was hard to miss.

bagwell

this is the only car I've driven with an automatic that downshifts and slows the car down when coasting....its a little overly aggressive in that regard -- in POWER mode that'd be fine but for every day driving its a little much IMO

lobuxracer

iTrader: (2)

It's even more annoying when trying to drive aggressively on a winding road. You'll need to re-learn your interface with the car to make it do what you want. Or disable VSC entirely.