TRexLex

Hi there, I have a 2011 Rx450H(135K miles) that I purchased new during the last "carpocalypse" for full MSRP due to the Japanese Tsunami. I have had a relatively trouble-free ownership, til now, and the car hasn't had any major accidents, however I have replaced the struts, experienced several bouts of non-starting due to battery dying and some other 100K+ major maintenance in the past two years. I'd like to hold on to the car at least past this recent chip shortage carpocalypse, however, I've had some concerning alerts that the dealer has not been able to figure out and that make me feel less secure driving the car.

In the last month I noticed my "Check Engine", "Check Hybrid System", "Check ABS" and "Check AWD" coming on intermittently and sometimes all at once, usually after a sudden stop or slowing down at the bottom of a hill to make a turn, or for no reason at all. The car also seems to slip of out driving mode in a way where I press on the gas and it won't accelerate; I experienced something like this when my clutch started slipping on a manual transmission car I've driven in the past.

The dealer charged me $600 to take my car apart (back seats) and examine the entire system; they told me there was sand/water that got in because a vent was frozen open. However, 20 miles from home on a 70 mile drive from the dealer, the check hybrid system alert came on again so I took it back to the same dealer again.

After the second visit the dealer said"

"The issue we are having with your RX is due to the hybrid inverter with converter assembly. What this part does is it converts the energy stored in the hybrid battery and converts it to power that the motors on each wheel can use to make the car move. When you were originally here, we removed the rear seats and panels to check the hybrid battery/ wiring/ and also one of the ecu’s for the hybrid system. We did find water intruded into the car from one of the body vents where the rear bumper was and got that vent fixed. We did find one of the connectors to had been corroded from the water that managed to get onto it and was able to fix that issue. When you brought your RX back this time we had a trouble code in the hybrid system for generator performance and hybrid voltage fault. With this we tested wiring and components and were able to rule out issues with the wire harness and the hybrid battery itself. At this point, we determined that there is an internal fault going on within the inverter assembly."

Has anyone else experienced this problem and can you tell me if I'm likely to find a solution to keep the car for less than $8000?

LeX2K

Did they say what vent? Did you see the sand and water or evidence of? There is a vent on the left hand side of the car its purpose is to allow equalization of cabin pressure. The hybrid controller is under the hood not behind/under the rear seats. Was the 12 volt battery checked? If it fails the car will have all manner of strange problems. If possible post a picture of the invoice you got from the dealer.

Has the car been flooded at any point?

TRexLex

The dealer invoice says from the first visit:

"Verified customer concern. Performed Health Check and found DTC for Hybrid System performance. Checked info code and found system moisture. Removed interior to inspect hybrid system and found signs of water entry but water has since dryed. Found corrosion on wire harness. Repaired Harness and Test Drove. System working as designed."

I appended a description of the inverter converter issue to my initial post.

Hayk

iTrader: (1)

The traction battery is under the rear seats, hence why they took that apart. It appears they found corrosion from water intrusion around that area. There are vents for the cooling fans of the traction battery. Maybe those are the vents that were compromised? It appears they’re saying the wiring and the traction battery are working okay after the first visit but the issue is now with the inverter in the front under the hood.

These cars are so complex it’ll be hard to find somebody else who can do that work properly. You may wanna get a second opinion from another dealer if possible.

703

Did you spill liquid in the rear seating area?

TRexLex

I'm sure I did at some point. I decided to pay for the repair. I'd rather stick with the devil I know than the buy a new car during carpocalypse

Aegean

This is one problem area with hybrids and there several inverter replacements in older Prius. It sounds intimidating for many shops with high school drop out mechanics due to high voltage. However, the labor is around 3 hours so say $500 labor and the part can be bought used for as low as $380 shipped. If you are a DIY person you can replace it easily as it involves only connectors, bolts and coolant refill. Many YouTube videos. Here is the used part online:

https://www.ebay.com/itm/10-Lexus-Rx...-127632-2357-0

This video show the process for an inverter replacement from a different hybrid just to get an idea what is involved.

TRexLex

Thanks, I wish I had gotten this earlier. Appreciate the info. I was told it involved very high voltage systems, and my go to after market mechanic declined.

Aegean

If you can not cancel the work order to the dealer it’s fine too as a new part properly installed is always the best option. If you can stop the dealer you could find a independent hybrid shop in your area to do this replacement. Even at full price with a guaranteed used inverter you might save several thousand.

salimshah

Mechanics when they enter the trade have a mechanical aptitude and then they get further training and acquire tools to do the work. Leaving hybrids alone, my guess is only 5% or less mechanics can handle the electronics involved in modern vehicles. That special skill is limited to a few garages and even if you drop your vehicle off at a shop, they promptly farm it out to the skilled garage.

Once you get into hybrids the training, specialized equipment, precautions are yet at another level. At dealerships they have specialists who only handle the the hybrid electrical systems.

I highly respect the mechanic who admits that the a certain work is out of his league.

The only issue I have with dealerships is "module/sub-system swaps". I don't blame them as they want customer satisfaction and not necessarily the cheapest solution [Typical Lexus owner is OK with it]. It is us DIYers who put in the extra time to learn and save $$$ spent.

Salim

Clutchless

There are independent hybrid specialists in New York, a few internet searches should find someone close by that could give you a second opinion.
Or it may be time to just trade it in. I would not invest that much money in an 11 year old vehicle.

Aegean

Did you replace the inverter?

TRexLex

Thanks for following up. I was planning to go along with the recommended repair however, upon further inspection the dealer said it was not the inverter, but actually the trans-axle assembly system that was causing the problem and the inverter was working properly. They replaced the trans-axle assembly, for the same cost. $6900, but my car seems as good as new and I still like it at 135K miles, so its unfortunate because I think my after market mechanic could have replaced that for far less but live and learn. It's still better than signing up for a new $60K car priced over MSRP or an overpriced used car with unknown issues. I am the only owner of the car and in my 11 years of ownership I've only had to replace struts and now the transmission.

riredale

Oh my goodness.

Nothing you can do now, but suggest you treat that dealer like a hot potato in the future and get a second Lexus opinion. "Trans-axle assembly?" This sounds very fishy to me.

Aegean

The good news is that you have a reliable car for several more years. The price might appear on the high side but the transaxle is brand new! Even a used one goes for around 2k plus 10-12 hours labor your mechanic could charge close to 4k still with a used part.

I was wondering about maintenance on the lifetime fluid. At 135k miles, how many times did you change the WS transaxle fluid if any?