Gs450H Check Hybrid Warning Problem With Generator

[rikardo82]

Hi I have lexus GS450H today got error Check hybrid system, it happened
like this, I stopped started to drive then energy monitor went blank
engine did not started it drive on electricity only I pressed
accelerator hard enough and engine should started. I stopped, restarted
hybrid system then engine started immediately (Battery was 2 bars) then
droved home 30 miles there was steep decent for some time Battery went
even to 7 bars so it charged but I expected to get it full it was ~20
mile down from 1.7KM to sea level, then when was in city noticed that
hybrid did not worked as always engine all time worked even when
stopped when started from complete stop also petrol engine worked, it
stops only when I'm stopping releasing accelerator pedal and when car
stop engine start to work again (Battery was 5-6 bars at that time) I
know there are charging cycles etc but no matter how long i droved it
petrol engine worked all time (temperature was +16Celsius air condition
off no heating etc) , for very short time when starting to drive
sometimes also only electric motor only work but very short time like
10-15 seconds. Then after 10 min when I was home started car again now
check hybrid warning disappeared I checked with computer I have
techstream software and there was current and historical error P0A92 -
hybrid generator performance I cleared that code also then test drived
again and still petrol engine all time worked, now went home waited like
30-40 minutes went for test drive again this time everything was
perfect petrol engine was shut down when droved in parking when
accelerated gently then also it was off etc. So this time hybrid system
worked perfectly fine.

Problem probably still is and I dont want to make now any unnecessary
trips if something like that happens one time it most likely happen
again. So what do you think is there potentially big problem ? I now
think about selling that car while it still running dont want repairs
costing thousands or maybe there is not so big problem?

Also want to ask if that was ok when I went downhill petrol engine
obviously was off and I braked with gearbox by switching gears down I
doubt its something wrong but still maybe it's not recommended to do so
maybe that somehow overheated generator? Also when just returned home
and car hybrid still badly worked when I switched hybrid on and engine
not yet worked (it went on after 10-20 seconds) there was some ticking
noise from bottom front? Is that normal? When just went for last test
drive seems that noise was not so big but still was...

Car has 110000 miles serviced in lexus dealer till 90000 miles last
service was done in other garage at 100000 miles I bought it very
recently droved only 500 miles.

Waiting for your answers thanks

[steve2006]

To be sure you would need to have the diagnostic fault codes read,there have been problems with the invertor units and the cooling system associated with it (apparently the pump fails and the unit then overheats).

[rikardo82]

To be sure you would need to have the diagnostic fault codes read,there have been problems with the invertor units and the cooling system associated with it (apparently the pump fails and the unit then overheats).

I wrote that code was P0A92 - (hybrid generator performance) I have also feeling it overheated becaue at time when it fail I went downhill and switched manualy gears down (at that time petrol engine was off) then stopped for some 10 min and then error was. When I got home car stayed like 40 min and then run normally. IS this pump expensive? Maybe I can perform some active test with techstream soft to make sure that is problem.

[ColinBarber]

If you use the 'gears' it actually turns over the petrol engine to provide additional engine braking, it wouldn't overheat the generator - it would disable the generator if the temp went too high and you would get an over temp error code - there are many temp. sensors all over the hybrid system.

First thing to check is to make sure your 12v Battery is ok. You get some strange faults if that is playing up.

If the display went blank it sounds more like an electrical / computer issue rather than something with the high voltage hybrid components. Maybe the software running in the system got corrupted in memory / bug etc. This could have triggered the error which then may have triggered a fail safe mode, then once you cleared the error it was ok again?

Pure speculation on my part, without any other error messages it is difficult to understand what happened. These may have been some freeze frame data stored along with the error code but that has probably been cleared when you reset the error. I think the only thing you can do is check out the 12v Battery, may be disconnect it to reset everything and wait to see if any faults reoccur.

[royoftherovers]

Hi I have lexus GS450H today got error Check hybrid system, it happened

like this, I stopped started to drive then energy monitor went blank

engine did not started it drive on electricity only I pressed

accelerator hard enough and engine should started. I stopped, restarted

hybrid system then engine started immediately (battery was 2 bars) then

droved home 30 miles there was steep decent for some time battery went

even to 7 bars so it charged but I expected to get it full it was ~20

mile down from 1.7KM to sea level, then when was in city noticed that

hybrid did not worked as always engine all time worked even when

stopped when started from complete stop also petrol engine worked, it

stops only when I'm stopping releasing accelerator pedal and when car

stop engine start to work again (battery was 5-6 bars at that time) I

know there are charging cycles etc but no matter how long i droved it

petrol engine worked all time (temperature was +16Celsius air condition

off no heating etc) , for very short time when starting to drive

sometimes also only electric motor only work but very short time like

10-15 seconds. Then after 10 min when I was home started car again now

check hybrid warning disappeared I checked with computer I have

techstream software and there was current and historical error P0A92 -

hybrid generator performance I cleared that code also then test drived

again and still petrol engine all time worked, now went home waited like

30-40 minutes went for test drive again this time everything was

perfect petrol engine was shut down when droved in parking when

accelerated gently then also it was off etc. So this time hybrid system

worked perfectly fine.

Problem probably still is and I dont want to make now any unnecessary

trips if something like that happens one time it most likely happen

again. So what do you think is there potentially big problem ? I now

think about selling that car while it still running dont want repairs

costing thousands or maybe there is not so big problem?

Also want to ask if that was ok when I went downhill petrol engine

obviously was off and I braked with gearbox by switching gears down I

doubt its something wrong but still maybe it's not recommended to do so

maybe that somehow overheated generator? Also when just returned home

and car hybrid still badly worked when I switched hybrid on and engine

not yet worked (it went on after 10-20 seconds) there was some ticking

noise from bottom front? Is that normal? When just went for last test

drive seems that noise was not so big but still was...

Car has 110000 miles serviced in lexus dealer till 90000 miles last

service was done in other garage at 100000 miles I bought it very

recently droved only 500 miles.

Waiting for your answers thanks

When did you buy it and from whom...........Trader or Private seller?

Regards

John

[rikardo82]

If you use the 'gears' it actually turns over the petrol engine to provide additional engine braking, it wouldn't overheat the generator - it would disable the generator if the temp went too high and you would get an over temp error code - there are many temp. sensors all over the hybrid system.

First thing to check is to make sure your 12v battery is ok. You get some strange faults if that is playing up.

If the display went blank it sounds more like an electrical / computer issue rather than something with the high voltage hybrid components. Maybe the software running in the system got corrupted in memory / bug etc. This could have triggered the error which then may have triggered a fail safe mode, then once you cleared the error it was ok again?

Pure speculation on my part, without any other error messages it is difficult to understand what happened. These may have been some freeze frame data stored along with the error code but that has probably been cleared when you reset the error. I think the only thing you can do is check out the 12v battery, may be disconnect it to reset everything and wait to see if any faults reoccur.

when I braked with gears petrol engine did not turned on but still I felt how car braked with gears,

Not only screen went blank but also petrol engine did not started maybe generator start to have some mechanic problem like with starters when they go bad sometimes car cant start somtimes can. Genertor in this hybrid also start petrol engine right?

maybe yes there is some software issue maybe my fault was that before 2 days I experimented with techstream tests perfomed Battery charge test put it on then off maybe there were not right conditions for that test I remember then I turned on hybrid system in P engine was running but Battery did not charged for some 20 seconds then it started to charge. Now in evening I again tested car switched on engine was running but did not charged Battery (in P position) it was ~ 1 minute then it stopped and I started to drive in electric mode when was on street then all worked as it should initially engine worked all time because Battery was only 2 bars and charged Battery in P or D position then when Battery was 4 bars electric mode again worked good.

I think I have no point at this time go to dealer they will tell all is OK right? Because now there are no errors.

[ColinBarber]

The petrol engine doesn't actual fire, but it is engaged with the pistons going up and down to create a load - it creates more load then the generator can create by itself.

Correct, the generator is used to turn over the petrol engine to start it.

Yes I don't think you will achieve anything by going to a dealer - Their tech stream software will say the same as yours - there are no errors.

You need to be careful playing around with techstream,

[rikardo82]

today went again for test drive with cold engine it started immediately but did not charged Battery when was in P so not good i think when on street it seems worked fine again most time at traffic lights engine was off even though Battery only 2 bars (usually engine then started) at supermarket parking Battery was again 2 bars after some driving in electric mode and then engine started and charged Battery also in Parking mode. So what I don't like now is that it does not start charge Battery from cold.

I put car with techstream soft in maintenance mode (from hybrid section) where it was supposed narrow down all parameters to trigger any error faster, in this mode check VSC appeared and when braked there was noise from brakes and some vibration. Went off maintenance mode droved to HighWay for some test drive fuel economy with cruise control 55 MPH was 43MPG pretty good accelerated to 120MPH pretty good as well :D then stopped at parking for 20 minutes started to drive and seems there was some whining noise when engine started after that seems no additional noises.

[rikardo82]

found interesting document about this error P0A92 it is about prius wondering if same would apply for GS450H???

seems Battery CURRENT SENSOR could be bad...

http://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/repair%20manual/04pruisr/05/21bpm/0a92606.pdf#page=1&zoom=auto

[ColinBarber]

The current sensor could be bad, but also the generator itself. Or a fault in the ECU triggering incorrect DTCs.