batzorig

Hello everybody,

I have posted a thread last year talking about problems with Check Hybrid System light on my 2010 RX450h. I have some updates as same problems have happened just today on 93F(34C) weather.

So far I have confirmed few things:

1. It only happens on hot days regardless of acceleration. I was in a stop and go traffic with various stopping duration for 8 hours. There were no high acceleration. (did not enter the POWER not even once)
2. During winters it is never a problem since I tried accelerating it to 110mph.
3. The light and the texts all go off after cooling down for few hours.
4. OBD scan only shows P3190 all the time.

So as I was slowly going through the traffic, I heard the beep and Check Hybrid System text came on with Check Engine light and a Triangle. The gasoline engine was not starting at all. As I was going alone in an urban area, I decided to push it further to see what happens. Only the electric motor was working. So after driving for ~1mile (1.5km), the Check Braking System text came up. Then the Steering wheel just stopped working almost immediately and Red light with Steering wheel came on just as I entered a cool indoor parking stop to cool my car down. I turned off my car immediately.

After about 5 minutes, I started the car again and this time the gasoline engine was working. Only the Check Hybrid System text and Check Engine light was on. As I used most of my electric battery to get there, the car started charging it with the gasoline engine. Then I noticed something was odd with the engine sound.

As some of you may know when you charge your battery with gasoline engine while stopped, the engine sound is just constant, almost on a same pitch. But this time the engine was slowing down, the pitch went lower, and it was not constant at all. I can include the sound file if you want, but basically the engine sound was like this:

1. Engine sounds just fine, just like it is working normally for 2 sec
2. Then engine sound pitch goes lower, and engine speed is all over the place. It speed up a bit, then slows down (although it is never the normal high pitched sound. It is always lower than that)
3. Then the engine just turns off, since battery levels have increased to 3 bars.

So that's all. If anyone had a similar problem, please help me. My first guess is fuel pump system, or spark plugs, but I'm not sure.

Sorry for the long post, and thank you for reading till the end.

vlad_a

Found this on Google:
https://www.google.com/url?sa=t&rct=...YRkO2Q&cad=rja

DTC No.
P3190

DTC Detection Condition Trouble Area

• Following conditions continue at a fixed engine RPM or a fixed
• length of time:
• 
  Communication with HV ECU is normal
• 
  Engine RPM is a fixed value or more
• 
  Engine start mode is not active
• 
  Target torque is a fixed value
• 
  Ratio of estimated torque against target torque is less than 20%

Trouble Area

• 
  Air induction system
• 
  Throttle body
• 
  Fuel pressure
• 
  Engine
• 
  Mass Air flow meter
• 
  Out of fuel
• 
  Engine coolant temperature sensor
• 
  Crankshaft position sensor
• 
  Camshaft position sensor
• 
  ECM

Droid13

I'm going to suggest you may potentially be seeing the results of the engine not sensing enough air, but due to extreme heat and elevation. I checked the weather for your area, 37C and 17% humidity. Very hot! And your elevation, while not in the clouds the extreme heat will also decrease your effective air pressure. Also, you say you were stuck in traffic. If your general weather forecast was 37C I know with the sun blazing off of road surfaces the immediate area temp could be about 5C warmer, plus if you aren't moving very fast the engine heat is not dissipated much at all. If I consider your elevation (Google says 1350M) @ 45C that is the equivalent of 2750M of elevation. Your engine has already lost 20-25% of it's HP in those conditions. The combined effect of extreme heat and low air pressure may be exceeding the sensors and computers range of operating values causing it to throw codes and run poorly based on data the computer just isn't programmed to deal with.

This might be a very crude test, but when it happens again and the engine is idling very roughly, try spraying a very, very, very fine mist of cool water near (not in) the air intake and see if there is any noticeable difference. Some high performance engines are known to use water injection to cool the air and engine components in similar situations. These systems don't actually just use regular water though, usually an alcohol or oil mixture, but this little test might just give a small indication the nature of the problem.

vlad_a

Nice one, Andy! Add in poor gasoline and we've got an unhappy hybrid.

iginoc

During last periodic maintenance check at Lexus, my 2010 RX450h (same age of yours) has been applied with a Lexus SB concerning the oxygen sensor, which has been replaced free of charge.. Although I detected no issues before, the engine now is more brilliant and responsive to the accelerator ( unfortunately more thirsty too) in fact I started to use the ECO mode that before I had to discard because the car was too lethargic, now it is quite acceptable. I have to say that the dealer put (for a fee...) an injector cleaner in the fuel tank so the differences which I perceive could be due to the injector cleaner action.

Ultimately, the reason of the issues you experimented could be the O2 sensor misbehaviour in hot and high operations, I would check at a Lexus dealer for the SB application if you have the opportunity..

batzorig

My stalling issues started 2 years ago. Last year while I was curious and checked the lexus.com/recall just for fun. Then I saw that my car was issued for recall for o2 sensor. Now the funny thing is just a week after the Check Engine turned on. It was the o2 sensor. Now as there was no lexus dealership here, I had to pay to get it shipped from US, and changed at toyota dealership.

I thought I fixed the issue, but nope! It came back to haunt me on hot days again.

Thanks though, I haven't read about any other 2010 RXh being recalled due to o2 sensor anywhere else. I thought mine was faulty or something. I should actually consider injector cleaner though, since most gasolines here are the worst.

batzorig

Thanks for the comprehensive answer Andy! It is surprising that you have made calculations based on my conditions. Bravo!

I don't think I will be able to try the test though, since the heat waves are ending. I will be able to try them next summer. It won't get much hotter. It will only get colder so Hurray! Fault free car! Thankfully my car is perfect even in -40 winters here

vlad_a

Funny you didn't say -40F or -40C.

JohnLX300

iTrader: (2)

I've had this same issue. It happened once after driving for about 3+ hours straight some mixed driving but mostly highway. As I went to mash the accelerator to pass someone on the highway the gas engine didn't start as it should have. I got the same code. P3190. I also have a 2010 RX450h. I brought the car to Lexus, the couldn't find the code and said it cleared itself out of the system. I was told to come back when it did it again. Well last weekend I was in Columbia, SC traveling to Charlotte, NC and the same thing happened. This time it was all highway but I went to pass someone and the engine didn't start right away. BUT this time I felt it, so I took my foot slightly off the gas, and saved it. The engine then started. Kinda weird. This happened another time at the end of the trip. I did the same thing. I have conflicting ideas on the culprit. I have an original battery, thought it was dying. It read 12.35 volts this morning. So I am charging it up tonight. I did order a replacement battery as I believe this battery is gone. My second idea was maybe the throttle body and mass air flow sensor needs to be cleaned?

JohnLX300

iTrader: (2)

Just wanted to add to this, since this issue is still ongoing with my vehicle. I just came back from a long road trip. I drove from Charlotte, NC to Orlando, FL and back. On the way down I had absolutely no issues with the vehicle. This was all highway miles. On the way back I stopped in Savannah GA for a hour or two and continued on my trip back. I start to fell a loss of power. If I would try to pass someone and place the pedal to the metal, the engine would go up so high in RPM and stay there and the car wouldn't accelerate. If I took my foot light off it would start accelerating again. This happened multiple times as I repeated did this to see what a possible issue is. Then 81 miles from home, the light show started.! I had my code reader ready in the car for this! I pulled ONLY a P3190 code. But I had one pending and three stored and one permanently stored. Since I only have the P3190 code....which is annoying, I did find one TSB from Lexus. L-SB-0155-11 This TSB does include another code.....BUT if something is heating up such as the rubber o-ring that is listed in the TSB and messing with the fuel flow this could be it! I have order the part.....its only $20! I hope it works, I will try and report back if it works, but I don't know when I will be able to try and replicate this again. I hope someone finds this and it works for them!