...or trying to start :-(
the "ready" and "check engine" light blink alternately when pushing start button.....but rx doesn't start.....not any dtc/fault code in the system, neither hybrid nor engine control units.
any idea what this could be? vehicle was standing for a long time, starter battery new.......any help will be highly appreciated ....because it is almost christmas.....lol

 

It's possible the traction battery is depleted too low for the system to start. In this case it may require a special battery charge by Lexus dealer or someone with the proper battery charger.

However, you mention the 12V battery is new. These are the manual's directions for starting the system if the 12V battery has gone dead or been disconnected:

After recharging/reconnecting the 12-volt battery The hybrid system may not start. Follow one or both of the following procedures:

●After opening and closing the driver’s door, wait 10 seconds and then attempt to start the hybrid system. (If the system does not start the first time, repeat the procedure.)
●With the shift lever in P and the “POWER” switch off, open and close any door and then attempt to start the hybrid system.

There is also an "emergency start function" the manual describes. Same as normal start procedure, except hold the power button down for 15 seconds.

 

@Droid17....great info.....i did as mentioned and the very first time it almost started. but any further attempt failed.....i got P3000 (battery control system) thereafter, cleared it and tried again....but unsuccessful........might it be the "main" battery is flat? how to get it charged without a lexus dealer? and where to connect a charger anyway?
so close and still not running......pity....

 

The special charge port is underneath the left side of rear seats, but I'm pretty sure only the special Toyota hybrid battery charger will work here, which may mean a tow.

If it was me, one last thing I'd try is disconnecting the 12V again for a bit, then try again. Might not help, but nothing really to lose at this point.

You didn't mention how long it was sitting. 2 or 3 months is usually ok, but getting up to 6 months or more, the NiMH batteries are known to deplete while sitting...

 

it was sitting since mid of september........i will try the reset/reconnect of the 12v....might a low fuel message play a role....? gauge still moves up, a bit above empty......

 

1. stop disconnecting 12V. Please. If you really want to reset ECU, simply pull ECU fuse for few minutes.
2.12V is likely low charge. That it's "new" means nothing as it is being charged off traction battery and if vehicle was not driven for several months and vehicle was stowed with traction battery at low charge, then you will have low charge 12V.
3. charge 12V. In the main fuse box under the hood there should be large (+) nut and (-) goes onto any known good negative. Or, you can charge 12V directly. I can only recommend a deep cycle compatible charger, as 12V has to be deep cycle. Unless you replaced it with something else.

 

now i get this warning/message signs in the cluster any idea what the message is?

 

Brake system warning (this is the non-US version of the warning light). May or may not be an actual brake system issue. Since the regen braking is part of the hybrid system, some hybrid related faults may trigger a braking system related code.