Car runs little while then shuts off

So about 2 days ago I replaced the front axle on the front passenger side, now it is popping up check awd system and check vacation system, and my rear electric motor is not operating any information on a sensor issue maybe?

107,000 miles, about a month ago, brakes started doing a vibration/shake when stopping in parking lots, parking spaces, garage, etc. all at very slow speeds, and the vibration would occur just before final stoppage. Braking at normal speeds seems normal without any loss. But the vibration at parking lot speeds is horrible.

mechanic has replaced left rear wheel bearings,rear strut assemblies and mounts(found right rear strut was broken),drained and refilled rear differential oil replaced Left rear wheel bearings,4 wheel alignment,and replaced 2 rear lower steering knuckle Control Rods. problem still exits when acceleration reaches 38 mph and above, diminishes some when braking, no thumping when traveling under 38mph

I'm hearing they are very expensive

Would be the beginning of my battery pack failing?

Brought it to the dealer. They said the oil pump for the hybrid system needs to be replaced. They also made the comment that the mechanic won't know until he/she removes the rear bumper if he/she needs to replace the wiring harness. It would be no more than $1600.00. I brought it to my mechanic who will do it next week. He didn't understand what they meant about the wiring harness. Any info would be helpful. I have 250K on the car. The mechanic has worked on it since I bought it with 25k.
Thanks in advance.

In Feb. 2012, I bought a 2006 RX400h which had a new hybrid battery. Since then, the battery has been replaced 3 times! In 1/2013, in 1/2014, and now 3/2015! What is up with the battery for this model? I can't believe there hasn't been some sort of recall by Lexus.

I backed into a tree and hit it only with passenger side mirror. Wasn't going fast as driveway was iced up. I had power steering before bumping the tree but lost it immediately after. Lexus dealer found codes C1532 & C1568. C1568 reset but C1532 came back in and won't reset. Also have the red "P/S Fail" light on dash. dealer says all connections and wires checked good.