Gs450H Loss Of Power

hybridbatterysolutions · March 18, 2016

Nothing to correct.

Very good work there Carl, I will be posting a you tube video of the conditioner soon, I believe there may be many other owners out there who could actively prevent Battery problems with one.

I thank you for your kind comments happy to help.

Richard

R8CGT · March 18, 2016

I can no longer see half of the pictures on my post. If it's the same for everyone then I will find somewhere else to post it and add a link.

mkbean · March 18, 2016

Yes Carl they are missing for me to. Please find somewhere to put these where we can keep these instructions around.

Although i'm hoping that an industry might spring up around this fix like it has for the hybrid batteries, i'm sure someone could make some good cash doing this fix for much less than replacing the pump or transmission.

Kosc300 · March 18, 2016

Awesome job. Just an fyi, after i did the replacement of the trans oil pump, i used a hand pump to put more atf in like most of you. However, i noticed that the transmission shifted a little rougher, and the transition between gas and electric was a bit harsher. I just did a transmission flush at lexus of manhatten for $350 and she's shifting much smoother now overall. The have a tool that can measure the proper amount of atf the transmission needs. The transition from gas to electric is much quieter and smoother now as well.

R8CGT · March 18, 2016

Thanks Komain. I'll look out for that. Cheers.

R8CGT · March 18, 2016

Seems you can't have more than about ten attachments! I've put the full write up in a blog post and linked to it from my earlier post.

happily1986 · April 12, 2016

Dear all,

Unfortunately I have a 2008 GS450H which is afflicted with the dreaded check hybrid system message. The techstream fault code too was the P2797.

Enquired with the local authorised dealer and they quoted me a staggering 6200 Singapore dollars for the auxiliary oil pump and they were looking at 2000 dollars for the labour fee as well.

Eventually I opted to purchase the part on an indent basis from a stockist. About 1200 dollars before VAT.

I would like to ask some questions if you guys don't mind.

1. Does the cvt transmission block really have to be lowered in its entirety from the vehicle just so the transmission oil pump could be swapped?

2. Anyone's transmission was in bad shape and an overhaul had to be done as a result?

3. I realised that the cruise control doesn't work. Anyone had the same experience as well?

Thanks!

Kosc300 · April 12, 2016

2 minutes ago, happily1986 said:

Dear all,

Unfortunately I have a 2008 GS450H which is afflicted with the dreaded check hybrid system message. The techstream fault code too was the P2797.

Enquired with the local authorised dealer and they quoted me a staggering 6200 Singapore dollars for the auxiliary oil pump and they were looking at 2000 dollars for the labour fee as well.

Eventually I opted to purchase the part on an indent basis from a stockist. About 1200 dollars before VAT.

I would like to ask some questions if you guys don't mind.

1. Does the cvt transmission block really have to be lowered in its entirety from the vehicle just so the transmission oil pump could be swapped?

2. Anyone's transmission was in bad shape and an overhaul had to be done as a result?

3. I realised that the cruise control doesn't work. Anyone had the same experience as well?

Thanks!

Sorry, im at work, so only short replies.

1. No it does not need to be lowered.

2. No. My car went into limp mode to protect the transmission.

3. Yes, my cruise control was not working either.

happily1986 · April 12, 2016

1 hour ago, Kosc300 said:

Sorry, im at work, so only short replies.

1. No it does not need to be lowered.

2. No. My car went into limp mode to protect the transmission.

3. Yes, my cruise control was not working either.

Thanks mate for your prompt reply. I appreciate the brevity actually.

How do i know whether the car is operating in limp mode actually? I do realise that the drive train seems to be retarded in response and I do notice that the ready light takes almost 10 seconds to steady itself.

Other than that, I have kept the car under 120km/h and noticed the fuel consumption was horrendous.

On another separate matter, I have had to change the agm Battery in the boot and I activated Lexus's road side assistance bla bla and the chap spotted the CEL as well as the dreaded message. He went ahead to use his techstream and confirmed for me the fault code is P2797 but he caution me against driving cos the vehicle might stall without warning.

I was done. I had been driving hybridless while waiting for the auxiliary pump to come but I had assumed that so long I don't do anything destructive to the transmission block, it will be fine.

And oh I am sorry for asking yet another question. What are the chanced that the oil pump controller driver governing the oil pump is kaput as well?

Kosc300 · April 12, 2016

You know you're in limp mode when the car won't go over 70mph. In my case, if I drove for more than 15min, the system would lower max mph to 60, 10min later 50mph, etc etc. Til it wouldn't drive at all. I'd have to pull over and let the trans oil cool for 20min to an hr and then continue driving. I believe Hanes was able to drive up to 70mph the whole time. Both of us were in gas only mode, no hybrid, so the gas mileage was bad.

The oil pump controller should be the first thing you check, as its easier and cheaper to replace. You can see our thorough experiences in the first few posts.

Hayne · April 12, 2016

Hi Junhao, sorry to hear you're having this problem.

On the positive side, it is repairable for only a few pounds, so not really a major problem.

You don't need a new pump; it will only be the 2 bearings front and rear of the impeller shaft and it's not difficult to repair either. It is such a simple design.There's not really much to fail.

No, the gearbox stays in place. Luckily, its quite easy to get to on a ramp. You will need 4 litres of transmission fluid (buy 5 in case), but only use genuine Toyota stuff. its only £10a litre, so best to use the right stuff.

The CVT gearbox has an overdrive gear, meaning it has 2 ratios and a CVT variable gearing. The 1st gear goes up to 80mph and the second gear goes from 35mph to 155mph. The CVT is not actually in limp mode, it just can't change to the 2nd ratio (its the hybrid management that shows the fault and limits performance). The engine is an Atkinson Cycle engine with variable compression ratio (simulated by the valves), built for economy, so that's why it only has power at high revs. From low revs, the motor gives you the power to take off. That's why acceleration is slow from a standing start when this fault occurs.

In fact, the Hybrid system id still operating, it just doesn't allow energy harvesting from coasting and braking, or all-electric drive. There is no reverse gear in our gearboxes. Reverse is done through the electric motor. Also, there is not starter motor either. The crank is turned by the same electric motors used for drive, so that's why it starts so smoothly and instantly. So, the Hybrid system is all working fine and charging from the alternator. Also, the air conditioning compressor is electric running from the 288V hybrid batteries.

Its normal for the cruise control to stop working until the fault is cleared.

I drove mine for 6000 miles before I worked out what was wrong with it. So no damage will occur to your gearbox; don't worry about that. Just use it until you fix it, but avoid starting off on steep hills going forwards, as you will find there isn't enough power to get you going!! If ever you do get stuck, reverse works up hills just fine!!

Hope you get it fixed soon!

Giles.

hybridbatterysolutions · April 16, 2016

On 27/02/2016 at 1:01 PM, Britprius said:

New member moved across from Prius Chat having just changed from a Prius to a GS450H.

Thanks Giles for the information on the pump motor bearings. I live in north Herefordshire, and would be happy to buy you a pint on behalf of the other members.

In time I hope to contribute much to this forum as I hope I did on Prius Chat. I have an electronics background that is useful working on hybrid systems. I also have Techstream so am able to read all fault codes, and am happy to read codes for anyone able to get to me.

A very big welcome!

Maf86 · June 28, 2016

On 12/25/2014 at 7:49 PM, Hayne said:

I should also mention what to look out for when your pump is due to fail.

These are my experiences;

About 2 months before my hybrid transmission oil pump failed, I particularly noticed a slow response when the gearbox changed the CVT torque multiplier ratio (i.e. equivalent to an overdrive gear).

About the torque multiplier: At about 55mph, the gearbox changes the ratio of the CVT to the high ratio (you will notice a short drop in power of about half a second) before continuing to accelerate. When decelerating below 35mph, the torque multiplier changes to the low ratio (again, you will notice a short drop in power/engine breaking, while this changes).

At this point, if the pump bearing is worn, the change is slower. This is most noticeable under hard acceleration, where the change can take a couple of seconds due to the pump motor struggling to turn properly, causing slower pumping of the transmission fluid (it is worth experiencing this now so you know what to look for in the future). I experienced a couple of times, the dash displayed the message 'Hybrid System Overheating' during hard acceleration. This too, was the pump failing to supply enough pressure to change the torque multiplier ratio in time. To try and overcome this just before my pump failed, I began taking my foot off the accelerator at around 55mph, just to give the pump a chance to supply enough to change ratio.

About 2 months later, while driving in electric only mode, the pump bearing seized and caused the car to grind to a halt, as there was no pressure.

If this does happen to your car, don't panic, just power the car off using the power button, then power on, wait for the READY light to go steady (takes about 10 seconds under the fault condition), then drive away as normal. The car will just be running in petrol engine only mode. The dash will show 'Hybrid System Fault'. The car will not drive at above 75mph. I drove my car with this fault for 5000 miles before I repaired it.

So, to summarise; if your car changes the torque multiplier ratio quickly under hard acceleration at about 55mph (could be up to 75mph, depending on acceleration), then the pump is functioning correctly. If you notice slow changes, or the overheating message, its worth replacing the bearing anyway.

I hope this will give GS450h owners a little more confidence as to the state of their pumps and what to look out for.

PLEASE NOTE; THIS IS JUST A SUMMARY OF MY EXPERIENCES AND MAY NOT APPLY IN THE SAME WAY TO YOUR CAR.

Giles.

Hi Giles,

I am experiencing quite a similar issue with my car, as you mentioned I am also noticing a slow response when the gearbox changes the CVT torque multiplier ratio especially under hard acceleration for the last 2 or 3 monthes, But in my case there are no error codes.

do you think that i should replace the bearing "I already ordered them online" ? or maybe the transmission fluid is low in my case?

Hayne · June 28, 2016

Hi Muthanna,

Not sure really, but preventative maintenance may prevent the car from stopping on the motorway!

How man miles has yours done? My bearing failed at about 155k. I noticed it failing about 2 months before.

If it was my car, I would change the bearings straight away. You may find your pump never fails. Bear in mind that if it does fail, you can still drive the car until you are ready to fix the pump. I drove mine for 5k before I worked out how to repair it. If you get the Hybrid System Overheating message on the dash when your foot is to the floor, then you know its time to replace the bearings. This is due to the car wanting to change ratio while retarding the power for a long time when the pump struggles, which causes the hybrid coolant to get hot (this should be a quick ratio change).

Regarding the transmission fluid level'; are there any leaks on the gearbox? if not, then the level will be fine (if it was leaking it would be visible under the car).

Cheers,

Giles.

Maf86 · June 29, 2016

Thanks for your quick reply Giles,

My car done 133k, and there are no visible leaks on the gearbox.

now i am just waiting the bearings, once arrived i will install them.

will keep you updated.

Cheers,

Hangie · June 29, 2016

When was the last time you changed gearbox oil ?

To be honest I would start with that normally. Please also remember that it is not just so straight forward change as in ordinary gearbox,

If your oil is in poor condition it can be harder to pump and may slow down gearbox reaction. There is even a chance that pump can go bad because of poor oil condition.

Maf86 · June 29, 2016

Hi Krzysztof,

I never did. I read that it shouldn't be changed.

Did you had the same issue "slow/delayed transmission response"? and if yes, does changing the oil resolved it?

cheers,

Hangie · June 29, 2016

No idea where you read it but for sure it is not true. Well it may be true if you will believe all that "car lifetime oil" but don't ask what is that lifetime.

Anyway if you check technical documentation for GS450H it is stating to:

- In severe condition inspect every 27k miles and replace every 54k miles

- In normal condition inspect every 36k miles. Taking same logic here as for severe I would say replace every 72k miles which would be consistent with what many other manufactures says - like Honda for example

Saying that first think I've done to the car when I bought it (it was 90k miles) was change of gearbox oil and rear diff oil (schedule says replace every18k miles) as I bet no one done it before. It cost me £250 at Lexus Guildford.

I didn't have any major delays or slow responses before but after change gearbox is more smooth with both ratio change and power (electric/petrol) distribution. I wouldn't be surprised that the most cases of broken bearing in the pump are due to oil which wasn't changed on time. It is easy to imagine it will loose it lubrication and may lead to bearing overheating and failure over time.

Finally in your case if you already got problems with bearings it may be too late for just an oil change but maybe it will convince someone else to do it on time rather than to wait. Also if I'm not mistaken you will need to change it anyway when pump will be dismounted. Lexus got special procedure to change gearbox oil and I doubt 3rd party mechanic will follow it, again it may or may not any create any problems but who knows :) Just please remember to use Toyota Genuine ATF WS.

Hayne · June 29, 2016

Hi Krzysztof,

I am too in favour of changing the transmission fluid regularly, as there really is no such thing as 'sealed for life' as manufacturer's lead us to believe.

However, just to clarify that the transmission fluid has no effect on the pump failure. The pump impellor and its housing is the only part that touches the transmission fluid and these never fail. The bearings run dry and are not submersed in the fluid at all and even if the fluid was thick, the pump would not be affected as it is on the impellor shaft mounted through the 2 bearings that moves and the strain would be through the additional current drawn from the speed controller, not any other part of the pump.

The bearings only fail due to wear and eventually break down causing the impellor shaft to seize. Nothing you can do to prevent it happening, unless you change them.

Regarding transmission fluid changes, you can only change half of it (about 4 litres) without removing the gearbox, so it will always be a half dirty. Oh and you are quite right; only use genuine Toyota ATF-WS. Its only £10 a litre anyway. Don't be tempted by cheap ATF !!

Cheers,

Giles.

Kosc300 · June 29, 2016

There's no way around changing some of the fluid. If you're changing the bearings, you'll have to drain most of the ATF anyway.

If you want to be thorough, you can drain the ATF. Replace the bearings yourself. Then have the car towed to nearest Lexus dealer, and have them to do a complete transmission flush. They'll advise against it, but just demand it.

Hangie · June 30, 2016

I wasn't aware about the internal build of the pump. But if bearings are dry then yes nothing you can really do.

Good thing for me at least is that pump was changed few times in car life cycle:

-35300-30032 - 05/2010 - onwards

-35300-30031 - 01/2009 - 05/2010

-35300-30030 - 09/2007 - 01/2009

-35300-30022 - 02/2006 - 09/2007

I believe that the most failures occurs for the oldest model which was mounted until 09/2007. In mine I got 35300-30031 so hopefully I'll skip the bearing changes :)

As for the oils change at a Lexus dealership - no one was against it or event suggest that it is not good think to do.

Hayne · June 30, 2016

Yes, you shouldn't have any problems with your pump Krzysztof. Unfortunately mine is a 35300-30022, which will failed on me and all will eventually fail with this part. Don't know how well improved the 30 and 31 are, but I assume they have uprated bearings.

happily1986 · August 7, 2016

GWS191-BEXQH

I came back to update that the CEL as well as the dreaded check hybrid system warning went away after i changed the auxiliary oil pump. As it turn out, the change of the transmission fluid also helped greatly in making the general jerkiness that i have come to associate with the car lately, go away as well. The ready indicator now comes on pronto and the cruise control now works.

Now i have got smaller issues to contend with.

1. The car seems to handle like a boat and i can feel every imperfection on the road. It wasn't like this before. I am trying to check and find out whether this car has APSSS. It is part 89241B right from the link below.

http://jp-carparts.com/lexus/partlist.php?maker=lexus&type=334110&cartype=2&fig=8419

2. It seem like the hybrid traction Battery pack isn't charging very well or rather it isn't holding charge very well. Of course the Battery indicator in the energy flow console isn't as exact as a percentage display. I took the car for a spin and i verifed the hybrid system works. The Battery charges and discharges according to the road situations i.e. (the Lexus Hybrid Drive LHD works) but i would find the Battery state of charge (SOC) changing rather rapidly to my concern.

When i thought the Battery is comfortably like 5 or 6 blue bars, it will rapidly change to 1 or 2 purple bars after helping to drive the rear wheels for a bit. I have yet to try to go for a really long drive to check whether i can get it up to green. How long in terms of a drive would you guys need to make it green from purple? The worst case scenario i think is to recondition the Battery. A new Battery pack is 3.5k USD

Britprius · August 7, 2016

You can check if the Apsss is working by removing a front shock absorber top cover, then remove the actuator " simple quarter twist". Turn car on, and have a helper turn sport switch on and off. You should be able to see the actuator drive tube move a quarter turn each time.

John

happily1986 · August 15, 2016

Thanks Britplus.

Seems like my hybrid woes still had a sequel. Now I have gotten the dreaded hybrid Battery fault code and I have taken the car to the workshop to swap out the old hybrid Battery pack for a new.

I ruled out having a reconditioned Battery or rehydrating the existing one. I reasoned that the tropical climate is a very trying operating set of conditions for the Battery pack so I was better getting a new pack.

I was quoted 3k GBP before VAT so I am very keen to know whether there is a way to check the Year of manufacture of the hybrid Battery modules?