How It Affects Engine Or Electric Motor?

[laryno]

Hi everyone,

Few days ago I left my lexus is 300h in 'drive' with handbrake on and didn't realise it while I have popped out to lock gate. It was for about 1 minute. Do you think it might affect or damage gearbox, engine or electric motor? I haven't got any warning lights on my dashboard and didn't notice any changes. Everything looks fine. I just don't know whether to have it checked in lexus service or it's not necessary. Thanks for your answers.

[rmccardal]

Highly doubt it would do any harm. Think about how often you sit stationary in drive just holding it on the brakes. Never done my autos any harm!

[MarksaCox]

Hey Iaryno,

I wouldn't worry about this at all. When I moved to an auto gearbox, there were times I drove with the handbrake on for a couple of seconds. No harm done.

Sent from my Iphone using Lexus OC

[Steve44]

I've driven off a couple of times with the footbrake still applied (by mistake). It bongs and a message comes up on the dash telling you how stupid you've been. I was surprised it let you drive off, as the footbrake was fully applied AFAIK

[ColinBarber]

Highly doubt it would do any harm. Think about how often you sit stationary in drive just holding it on the brakes. Never done my autos any harm!

that is slightly different because with your foot on the brake the hybrid system isn't energising the electric motor.

I wouldn't worry. All that happened is you wasted a bit of Battery energy. The electric motor will shut down if it gets too hot, long before it does any damage.

[rmccardal]

Pretty sure the hybrid system also recognises when the parking brake is engaged.

[para999]

do these not have hill assist so driving off with the handbrake on should not make any difference. it was demonstrated to me on a recent test drive. most cars fitted with electronic handbrake( which this would be classed as owing to the electronic release button, regardless of the manual application in the first place) have this as a safety feature especially for hill starts.

[ColinBarber]

do these not have hill assist so driving off with the handbrake on should not make any difference. it was demonstrated to me on a recent test drive. most cars fitted with electronic handbrake( which this would be classed as owing to the electronic release button, regardless of the manual application in the first place) have this as a safety feature especially for hill starts.

They do have hill start assist but that doesn't have anything to do with the parking brake. It also only engages for two seconds.

[para999]

sorry to disagree here but that is exactly what hill assist is for its so you don't have to try to find the bite point ( as done with a manual handbrake and clutch) whilst selecting drive or even already in drive and accelerating at the same time.it allows you just to drive off and the handbrake will hold for seconds then automatically release. the reason I know is because all of my auto cars have had this function when fitted with an auto handbrake.

the point to note is that in order to use this function you do have to press the accelerator to drive off.

[ColinBarber]

Pretty sure the hybrid system also recognises when the parking brake is engaged.

It doesn't, just tested it.

[para999]

ok have to admit I might be confusing things as different manufacturers have different wording and features not in other manufacturers details. the true definition of hill assist could be the automatically held footbrake pressure once the pedal is released for a very limited time. whilst in other manufacturers the wording of hill assist could be classified as the handbrake holding and not having to manually release it when applied. ( which I was referring too). the manufacturer of my present car is referring to the handbrake release whilst it appears from doing a search on the net that lexus use this term to describe the automatic brake pedal pressure feature. as I said in a previous post I have not yet taken delivery of my lexus so in the lexus sense I could be wrong with the wording and meaning that I used.

[Steve44]

IS has a mechanical foot operated "hand" or parking brake. GS has the elec-handbrake, something I wished they'd engineered into the IS as my previous car had one and it was fab. Can't say I've noticed mine doing proper hill-hold assist. Its an automatic, so it just sits there on a incline if I take feet off the brakes, or creeps if on the flat or downhill. Never rolled back to my knowledge.

[Steve44]

Pretty sure the hybrid system also recognises when the parking brake is engaged.

It doesn't, just tested it.

It does - if you drive off with the footbrake still on, it bongs away and a message comes up in the dash telling you and asking that you take it off.

[ColinBarber]

Pretty sure the hybrid system also recognises when the parking brake is engaged.

It doesn't, just tested it.

It does - if you drive off with the footbrake still on, it bongs away and a message comes up in the dash telling you and asking that you take it off.

It isn't the hybrid system that is bonging and we aren't really talking about driving off with the handbrake on here. The OP has stated that he got out of the vehicle with it still in drive and the handbrake on, and asked if this would do any damage.

The hybrid system doesn't know about the handbrake - it will continue to provide power to the electric motor when in drive unless your foot is on the main brake. When your foot is on the brake pedal, all power is cut to the electric motor, this isn't the case with the parking brake. However it won't damage the system as the current supplied to the motor is limited, whether the motor is stalled or not.

[ColinBarber]

ok have to admit I might be confusing things as different manufacturers have different wording and features not in other manufacturers details. the true definition of hill assist could be the automatically held footbrake pressure once the pedal is released for a very limited time. whilst in other manufacturers the wording of hill assist could be classified as the handbrake holding and not having to manually release it when applied. ( which I was referring too). the manufacturer of my present car is referring to the handbrake release whilst it appears from doing a search on the net that lexus use this term to describe the automatic brake pedal pressure feature. as I said in a previous post I have not yet taken delivery of my lexus so in the lexus sense I could be wrong with the wording and meaning that I used.

Hill assist on the IS keeps the brakes engaged (not the parking brake) for up to 2 seconds when you release the brake pedal to avoid the vehicle rolling back. It only operates this feature when it detects the vehicle is on an incline.