Problems with 2006 Lexus RX 400h POWER TRAIN

2006 lexus rx400h totally shutting down while i was driving on i4 today. no power steering, no power brakes, engine died and luckily i was able to coast to a safe place from 70mph! right before it happened, the check engine light came on, the engine misfired, then all of the lights on the dashboard came on including the check vcs, check hybrid and check anti-lock. had to have it towed to our mechanic because it wouldn't start and could not be driven onto the tow truck. codes that it threw said it was a high voltage system regenerative malfunction and a bad engine coil. it was a very dangerous situation with it shutting down on the interstate and i had no control what so ever! this was the second time this happened to me in this car and the computer was replaced the week after i purchased this car used in october 2017.

I was traveling 60 mph on the highway and my display started reading "check hybrid system" and "check vsc system" simultaneously. i searched and saw there was a recall for this exact issue (intelligent power module inside the inverter module) for certain vehicles of my exact make/model/year but for some reason my vehicle is not on the recall list. i took it to the dealership and they said the regular 12 volt car battery was the issue so they replaced it and the light went off and the car tested normal for several days however when traveling on the highway about a week later the same lights came on again.

The car is a hybrid. it would not start (the ready light would not come on), therefore it was inoperable. fortunately, the car was parked and did not die while driving. if it would have died while driving, many dangerous possibilities could have incurred. after having it towed to a lexus dealer in columbus, the source of the problem was diagnosed as water in the hybrid battery area. after lengthy discussion with lexus service personnel, they concluded that "welds" near the hatch hinges had come apart, which allowed water to seep into the interior of the car to the hybrid electronic controls. lexus service had experience these problems before, and had guessed at a variety of reasons (such as excessive opening and closing of the hatch, wind catching the hatch while it was open, and other lame reasons). there is no ticker on the hatch to count how many times it was opened nor what there any gust of wind that would have cause the welds, two welds, to break allowing water to seep into the car. my conclusion is that since the problem has occurred before, that there is either a manufacturing issue, an engineering issue, or both. i am neither an expert in these areas, but do have some common sense. lexus corporate or the dealer would not confess to the wrongdoing and therefore i had to shell out over $1600 in repairs. they wanted another $1100 to re-weld the 3 inch gap on both sides with painting included. due to the expense, i had to opt for using silicone to seal the gaps and am forced to drive the car in dry weather. *js

Leakage of coolant from the radiator discovered and in less than 50 miles an engine warning light lit, indicating failure of the hybrid synergy drive system , namely the hybrid inverter. vehicle was brought into a lexus dealership and the radiator and inverter were replaced. *tr

Driving at highway speed and car shuddered and lost power and all the "check" lights came on. dealer diagnosed inverter failure. *tr

Driving at 40 mph, vehicle engine stopped,shut down, power steering and brakes lost power assist. *tr

Driving down the road. stop at a stop sign on a very steep hill. start to pull out on to a very busy road. while giving the car gas to go it completely goes dead. nothing will work. put the car in neutral and backed it down the steep hill to a flat surface. without power steering or brakes. *tr

Vehicle was normally maintained and lightly driven. one year of age of the vehicle, when driven on level dry surfaces, the braking of the vehicle became erratic and remains erratic. in everyday use the vehicle will tend to overbrake or underbrake depending upon the mechanical loading of the hybrid drive. the onboard firmware is not properly accounting for integrating the stopping power of the brakes and the hybrid drive. this causes driver confusion and in some cases hazardous failure to brake conditions when the hybrid drive unexpectedly and erratically ceases it's contribution to the braking force of the vehicle. i.e. if the driver does not immediately compensate, the vehicle will lunge forward at low speed and within a few feet of pedestrians and other stopped vehicles in traffic. the dealership states that nothing can be done and that erratic/loss of braking is normal for this model. there are no recalls or sbs posted to upgrade the firmware, braking/hybrid drive systems. lexus rx400h, 2006 model. *tr

Dt*: the contact stated the vehicle does not gear down while going down an icy road. there are no 1st, 2nd or 3rd gears. there is no way to stop the vehicle from hydroplaning. the dealership determined that this is the way the vehicle is designed to operate. the contact no longer owns the vehicle and feels this is a safety hazard. updated 05/10/6. *jb