Bobomo

2006 RX400h, AWD. Relatively low miles (54k). Drive train is well mannered at all speeds, except when I'm cruising flat at exactly 40 there is this weird surging and hesitation feeling like the transmission can't get the speed right. The speedometer doesn't really move when this happens, it's a very subtle feeling.

Any ideas? Engine mounts?

maseace

Could be the gas engine cutting in and out, since that's about the speed where it will go into EV "stealth mode." There is a slight tug each time the engine starts back up. If you had a tachometer you would see the RPMs go to zero during this. Check the energy flow display and see if the arrows coming/going from the engine and battery change directions next time you feel this. If you are light on the gas pedal and not going uphill, you can get it to stay in electric-only EV mode for a couple miles around 40mph. At 42 mph and above, the gas engine comes on no matter what.

Bobomo

That's a thought - I'll check the display next time it happens. Usually I can hear and feel when the motor kicks on, but that's typically during acceleration. Thanks.

joedaddy1

iTrader: (1)

check the rx400h TSB's..

this issue has a TSB out for it

Frankphurs

We are having a similar problem with our 2006 rx 400h. Can you direct me to the correct TSB?

Bobomo

I couldn't find a TSB for the issue except for the standard Toyota "surging" issue related to stuck gas pedals. I think the first response is correct. I notice the feeling of surging is correlated with the ICE turning on and off around 40mph. I don't notice it any other time.

joedaddy1

iTrader: (1)

here is the TSB:

http://st.club-lexus.ru/attach/u/e4426448.pdf