Rx 400H Hybrid Transmission Fault

[Gaga]

Hi,

I have a RX400h which has done 17,000 miles and it is presenting symptoms which I find concerning and would like to hear if others have had similar symptoms.

There are 2 main symptoms:

1. When decelerating on a gentle slope at 30-40mph, the hybrid is regenerating the Battery and braking the speed plus my foot on the brake pedal is very gently slowing the vehicle as well. It feels as if the brakes "let go". I am sure my foot has not moved and even if it had why does the regeneration also "let go". This seems to be more frequent in the winter months but is intermittent.

2. The display for energy should display 99.9mpg when running on electric only or when regenerating. It does not but actually displays random numbers for mpg ranging from 21 to 67. Again intermittent and this also seems to be more frequent in the winter. Marsh garages seem to me to ignore this problem and instead concentrate on delaying a response to the rusty dog-guard. I do not know if this is linked but the mpg has dropped as this has got more worse from 32 to 25 mpg.

I am now concerned as these seem to be similar to the problems experienced in America.

If you have experienced similar conditions and can give me a lead as to how to have them put right I will be very thankful.

[MartyCee]

I have experienced a similar braking sensation with my RX400h. Until now I have been told & therefore assumed, it was an idiosyncratic sensation of the hybrid system.

It has never been dangerous &, in my case, not really seasonal.

It is however there & most obvious under gentle braking. I can best describe it as being akin to the hybrid re-generation being cut (which it does at about 3mph)& therefore requiring more input on the brakes to maintain braking effect.

Fuel consumption will be higher in the winter months, due to the need for the engine to run more to keep the heater warm & the hybrid Battery charged (it powers pretty much everything in the car, not just the electric motors) & the extra use of heated rear window, fans, heated mirrors, etc. To be fair this is something that affects every car on the market, the difference being that they (mostly) supply power of an engine driven alternator, not a hugely capable Battery.

As to the dealers' attitude.......... Lexus don't want it widely publicised & won't admit to it, but there are some dealers are definately not up to the standard that Lexus would have the public believe.

Not surprising really, we are talking about the car retail industry, an industry that has had a very poor image for many years.

I had some very serious issues with my local dealer & ended up using another some 35 miles away. Lexus (Belinda Poole herself) simply washed their hands of the issues & said it was between me & the dealer. Lexus Europe backed her up.

In my case it back fired big time for Lexus. 8 months later I was in control of a pan-European budget for a loan car fleet for a luxury leisure group, net result, 45 BMW 1 & 3 series ordered & the previous Toyota fleet thrown out. Thus far no problems & support equal, if not better to that from Toyota/Lexus (who were in the running until the day I was appointed!)

So I would approach another dealer & explain the problems you are having with the car, without winding yourself up over the selling agent in the process - this alternative dealer should be part of the solution, not part of the problem.

If you are still unhappy you do have the option of seeking an independant engineer's report. However, a word of caution. Before you go that way return the vehicle to the supplier & state that you want them to check the systems out thouroughly & give you their written evalution as to the state of the vehicle's systems.

If they refuse or if they find nothing you should then advise them in writing that you intend to seek an independant engineer to inspect the vehicle & should they find anything wrong you will seek redress for the cost of that report together with an appropriate sum for compensation due to their inadequacies.

Hopefully it won't come to that. But never assume that a dealer's word is gold. If they supply you with a print out showing nothing is wrong then they have given you their position in writing. The next move is yours.

Do everyone a favour though. If you find there are issues with the car &/or the dealer, post that info as widely as you can. Sadly Toyota/Lexus have a very slow witted means of handling problems, often preferring the "it'll go away" approach.

America has made you concerned & rightly so. Because the problem was/is quite serious in potential. But, what really did the damage to Toyota was the way the problem & associated concerns & publicity was handled. Hopefully they have learnt, an opportunity never goes away, it just goes somewhere else, but I wouldn't bet on it.

[Gaga]

Thanks MartyCee for your response.

With regard to the braking issue, this has got more frequent as time has gone by and has never happened at 3mph but happens in the 30-40mph. Given the agents attitude it does not give me confidence that something serious will not happen.

Fuel consumption was OK at 33mph but has dropped to 25ish, and as I live in Cornwall winter does not affect it especially to that degree and was dropping through the summer. However it is my feeling that the low fuel figure and the false reading on the displays is an indication that the hybrid system is not functioning properly and therefore I question is this going to be very costly when it is out of warranty.

I wrote to Lexus (Belinda Poole herself) and she sent me a circular letter saying, what I interpreted, as we at Lexus are only here to supply the agents with cars. They will not get involved with my problem with an agent.

I have asked the agent repeatedly for prove that the car is 100% as they say the car is fine. The best I have had is an email listing several points, that are OK, BUT these points are not the ones that I have complained about. It is like going to your doctor and saying I have hurt my foot and he tells you there is nothing wrong with your shoulder. Going to another dealer, as they know, is difficult as I live in Cornwall and Plymouth and Exeter are owned by the same company. The next dealer is 3 hours drive.

Because I will not take my car back until they convince me it is OK they have now said they are charging for storage. I feel that the old saying “I, the agent, don’t mind and you don’t matter” is appropriate after all the web promises, the sweet-talk and promises made.

I have even received emails promising something by a certain time only to find that when the time comes, and goes, even after chasing several times it is hard to get the original promise.

Do you think that they are swamped with problem cars or is there another reason?

[JBPRX400h]

Thanks MartyCee for your response.

With regard to the braking issue, this has got more frequent as time has gone by and has never happened at 3mph but happens in the 30-40mph. Given the agents attitude it does not give me confidence that something serious will not happen.

Fuel consumption was OK at 33mph but has dropped to 25ish, and as I live in Cornwall winter does not affect it especially to that degree and was dropping through the summer. However it is my feeling that the low fuel figure and the false reading on the displays is an indication that the hybrid system is not functioning properly and therefore I question is this going to be very costly when it is out of warranty.

I wrote to Lexus (Belinda Poole herself) and she sent me a circular letter saying, what I interpreted, as we at Lexus are only here to supply the agents with cars. They will not get involved with my problem with an agent.

I have asked the agent repeatedly for prove that the car is 100% as they say the car is fine. The best I have had is an email listing several points, that are OK, BUT these points are not the ones that I have complained about. It is like going to your doctor and saying I have hurt my foot and he tells you there is nothing wrong with your shoulder. Going to another dealer, as they know, is difficult as I live in Cornwall and Plymouth and Exeter are owned by the same company. The next dealer is 3 hours drive.

Because I will not take my car back until they convince me it is OK they have now said they are charging for storage. I feel that the old saying “I, the agent, don’t mind and you don’t matter” is appropriate after all the web promises, the sweet-talk and promises made.

I have even received emails promising something by a certain time only to find that when the time comes, and goes, even after chasing several times it is hard to get the original promise.

Do you think that they are swamped with problem cars or is there another reason?

[JBPRX400h]

Thanks MartyCee for your response.

With regard to the braking issue, this has got more frequent as time has gone by and has never happened at 3mph but happens in the 30-40mph. Given the agents attitude it does not give me confidence that something serious will not happen.

Fuel consumption was OK at 33mph but has dropped to 25ish, and as I live in Cornwall winter does not affect it especially to that degree and was dropping through the summer. However it is my feeling that the low fuel figure and the false reading on the displays is an indication that the hybrid system is not functioning properly and therefore I question is this going to be very costly when it is out of warranty.

I wrote to Lexus (Belinda Poole herself) and she sent me a circular letter saying, what I interpreted, as we at Lexus are only here to supply the agents with cars. They will not get involved with my problem with an agent.

I have asked the agent repeatedly for prove that the car is 100% as they say the car is fine. The best I have had is an email listing several points, that are OK, BUT these points are not the ones that I have complained about. It is like going to your doctor and saying I have hurt my foot and he tells you there is nothing wrong with your shoulder. Going to another dealer, as they know, is difficult as I live in Cornwall and Plymouth and Exeter are owned by the same company. The next dealer is 3 hours drive.

Because I will not take my car back until they convince me it is OK they have now said they are charging for storage. I feel that the old saying “I, the agent, don’t mind and you don’t matter” is appropriate after all the web promises, the sweet-talk and promises made.

I have even received emails promising something by a certain time only to find that when the time comes, and goes, even after chasing several times it is hard to get the original promise.

Do you think that they are swamped with problem cars or is there another reason?

Hi Gaga

The feeling of "let go" when gently braking can happen if a wheel hits a bump or a pothole. It is a quirk of the regenerative braking system changing over to "normal" braking and isn't serious - just takes a bit of getting used to! Don't forget the plus side of the regenerative braking system is incredibly long lasting brake pads as they are little used!!!

Regarding the fuel consumption. It is normal for you to notice a drop in the colder months (even in balmy Cornwall) as the engine runs more often to provide cabin heating and to keep the catalytic converter up to operating temperature.

Just a thought though. Have you had the 12V Battery disconnected for any reason or has its voltage dropped below 7V at any time? If so you may need to carry out an "ISC learning procedure" to reset the engine's normal idling setting.

Here is a link to a post from Lemon in Canada on the USA forum.

http://us.lexusownersclub.com/forums/index.php?showtopic=58930

Hope that helps

JBP

[malcolmn5143]

I have had the same thing. Just had a new Battery and performed the learning procedure. Definately works, so give it a try.

[Mr Pants!]

I have exactly the same thing on my RX400h where under light braking I could swear the brakes stop working for a split second, but it is always on bumpy surfaces and as previously mentioned I put it down to that, i.e. the wheel bumps off the surface of the road and loses traction for a split moment or my foot is bouncing fractionally on the brake pedal.

I am not overly concerned as it has never happened when I really did not want it to, its always as I am gradually braking, slowing for a queue of traffic or junction.

It is a weird sensation and my wifes BMW does not do it, it only seems to be noticeable on the RX

[Gaga]

I have exactly the same thing on my RX400h where under light braking I could swear the brakes stop working for a split second, but it is always on bumpy surfaces and as previously mentioned I put it down to that, i.e. the wheel bumps off the surface of the road and loses traction for a split moment or my foot is bouncing fractionally on the brake pedal.

I am not overly concerned as it has never happened when I really did not want it to, its always as I am gradually braking, slowing for a queue of traffic or junction.

It is a weird sensation and my wifes BMW does not do it, it only seems to be noticeable on the RX

Thanks for response to these notes.

Because initially I said to Lexus that I did not want the vehicle back until they recognized the faults I was concerned over they now insist in a £900 charge, that I say is bogus to have my vehicle back - I see it as holding me to ransom over if I want my vehicle back. They have become incredibly aggressive and inflammatory, to my way of thinking, which sadly to me confirms that they have a serious problem once these symptoms show, either to put right or very expensive in the future. My car was sold to me with 3 years warranty and 5 years on the hybrid system. I now wonder when the hybrid starts and "car" electronics take over. I was sucked in when I bought the car by all the promises of caring for our customers and nothing is to much etc etc.

A car of this quality should have no faults and there should never be any argument and I suggest that you register your complaint in writing (recorded), even if it is just to help those of us who have this and other problems. It may help you if your vehicle is involved in an accident as Lexus's attitude will be to deny all knowledge of it.

[ColinBarber]

You don't have any faults. As has been previously stated by JBPRX400h the brake feeling is a quirk of the braking system used by the vehicle, they all do it. MPG not at 99.9 when on electric or regenerating is because the petrol engine is still running and consuming fuel. This happens more in the winter because the engine is used to provide heat in the cabin. If the engine isn't up to temperature then it runs rich (choke) so the mpg if worse. If you are going fast enough when you come of the gas then you will always see 99.9mpg as the real figure is several hundred mpg but if you are going slowly then the fuel being used by the engine brings the mpg figure below 99.9.

[Duncan Roberts]

Gaga: You are the one that is being unrealistic. You have sufficient evidence that there is no fault with the Car, just in your mind. Either the take car back and enjoy or sell and cut your losses. However whatever you do, do not blame Lexus.

[sowlerthjh]

You should read the posting from "bobthebuilder" on 18th January 2011.

He was involved in an accident on the A1 caused by brake failure!

See http://www.lexusownersclub.co.uk/forum/lofiversion/index.php/t66858.html

[rynd2it]

I have exactly the same thing on my RX400h where under light braking I could swear the brakes stop working for a split second, but it is always on bumpy surfaces and as previously mentioned I put it down to that, i.e. the wheel bumps off the surface of the road and loses traction for a split moment or my foot is bouncing fractionally on the brake pedal.

I am not overly concerned as it has never happened when I really did not want it to, its always as I am gradually braking, slowing for a queue of traffic or junction.

It is a weird sensation and my wifes BMW does not do it, it only seems to be noticeable on the RX

My US RX400h has done the same thing occasionally ever since I have had it (31000 miles in 3.5 years) - almost always when the car is cold and it's the first brake application, more so if the air is damp. I found that releasing the brake pedal and immediately reapplying it worked, the regeneration brake engaged and all was fine. Not noticed anything with the consumption though but I rarely watch that part of the display. Overall consumption has remained static at 23.6 mpg (US gallons).

I did question my dealer when I first noticed it, they checked the car thoroughly and found no faults. Lexus dealers in the US right now are paranoid after that crash involving a loaner car fitted with after market floor mats which jammed the accelerator pedal. That happened locally and got a huge amount of coverage so they are extra cautious when dealing with reports of anything to do with braking or acceleration.

I have stopped worrying about it as it isn't serious and I have the dealer report (somewhere) giving the car a clean bill of health.

Cheers

David