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Lurching on startup?

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Old 01-30-13, 03:13 PM
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Ciege
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Default Lurching on startup?

This has happened a few times recently. When I first turn on my RX450h and remove my foot from the brake after it has gone to ready, when the ICE kicks in the whole RX will lurch a few inches. The RX is always in park and the e-brake is on. It lurches enough that I believe if the e-brake wasn't on or the RX wasn't in park it would hit the wall I am parked in front of.

This doesn't happen every time, more like about 10% of the time. Has anyone seen similar? Is this indicative of another, more severe problem?

Thanks!
Old 01-30-13, 03:35 PM
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That sounds pretty unusual and a good reason to go straight to your dealer's service dept 1st thing in the morning. That kind of thing is for warranty. That's what it's for. I've never heard of what you just described.
Originally Posted by Ciege
This has happened a few times recently. When I first turn on my RX450h and remove my foot from the brake after it has gone to ready, when the ICE kicks in the whole RX will lurch a few inches. The RX is always in park and the e-brake is on. It lurches enough that I believe if the e-brake wasn't on or the RX wasn't in park it would hit the wall I am parked in front of.

This doesn't happen every time, more like about 10% of the time. Has anyone seen similar? Is this indicative of another, more severe problem?

Thanks!
Old 01-30-13, 09:26 PM
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Droid13
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This has been discussed several times over the years on the Camry Hybrid forums and I believe it is a known occasional idiosyncrasy for some cars with the Toyota hybrid systems. It's exactly as you describe, the engine spinning up while in Park with the foot off the brake. It only seems to happen when there is no load on the engine (ie in PARK) I experienced it once with my old Camry Hybrid. As far as anyone said, it only involved some movement within the play of the PARK lock only and never a case of it driving away on you. As long as you are parked away from any obstacles within the limit of the play in the PARK lock, you are fine (which pretty much applies to any parking job I guess).

I don't recall hearing if anyone actually had a dealer fix anything to address this issue, but never hurts to check with your dealer anyway if it bugs you.

I think the lurch is actually caused right at the moment of transition as the engine fires. The engine is always connected to the front wheels, but how much power makes it there depends on the loads created by the two electric motors (which are also always connected). The system is basically a balancing act of the 3. During this instantaneous moment the 1st generator has to switch from powering the engine (spinning up for start) to being powered by the engine (battery charging, etc.), with just a tiny nudge of power sneaking out to the wheels once in a while. Why it happens only sometimes, and only with some cars, I don't know.

I link you to one of those discussions for your info:

http://www.greenhybrid.com/discuss/f...-parked-17382/
Old 01-31-13, 07:58 AM
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From what I can tell, this lurching doesn't only occur on start-up. This has happened to me on occasion at shut-off.
After pulling into my garage with only the electric motor functioning and with the hybrid placed in park with foot on the brake and pressing the start to disengage, my vehicle will lurch ever so slightly. It can be quite disconcerting.
Old 01-31-13, 08:37 AM
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kitlz
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I've experienced the lurch a few times about 10 seconds after starting the RX with my foot off the brake and in park. Only once did it alarm me. Since it doesn't happen often, I'm not too concerned. But please let us know if you find out anything.
Old 02-01-13, 07:19 AM
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Thanks all for the posts and links. I've not gotten to the dealer yet, but plan to soon. In the mean time I've made a conscious effort to keep my foot on the brake upon start up until the ICE kicks in.
Old 02-11-13, 11:20 AM
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This is funny as it happened to me just now and I wanted to ask everyone the same question. I was parked and after a couple of minutes, the engine kicks in and feel the car is going to move forward, then I feel as if the engine is strugling to have a smooth purr, as if there is something in the fule line.
I plan to take it in soon for a check up and hope that it happens at the $tealer. I do not see any check engine light.
Old 02-11-13, 05:17 PM
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Common on the Prius too
Old 02-19-13, 02:37 PM
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Had it on the Prius as well as the RX. It is normal considering the combustion engine is sandwiched-in between 2 electric motors, one of which as at a standstill and directly connected to the driving wheels while the other spins the engine to start.

Using a parking brake should mitigate this issue.
Old 11-04-16, 07:53 PM
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Try after startup, remove foot from brake until ready to shift gears
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