IS300h hybrid system fails to start

valanade · April 7, 2016

Symptoms seen were:

Door mirrors unfold sluggishly.

On plugging in seat belt Memory Seat and/or Steering Wheel sluggish or fails to reset to Drivers Memory position

On pressing Power button, hybrid system ready light doesn’t come on and warning alarm sounds followed by message on dashboard saying “Hybrid system failed to start, Select P”

Car is already in Park (P)

The above symptoms appear randomly but are consistent if car is not used over a weekend or after about 15 mins listening to the radio with the power mode selected to Accessory.

On it failing more regularly I measured the 12V Battery voltage at the starting connection in the fuse box which read 10.2V DC.

Once I managed to get the hybrid system to start then the 12V system voltage was steady at 14.4V irrespective of whether the engine was running or stopped. Believe that once the hybrid system starts the 12V system is maintained from the main traction Battery.

On taking the car in for service (2years, 15000 miles) the fault has been diagnosed as a sick cell in the 12V Battery.

The quotes from Lexus Plymouth are “it is not possible to break the hybrid system”, “we have never seen a Lexus Battery failure”. A replacement unit is not immediately available and is on “back order” (whatever that means) as apparently they don’t fail so am now driving a hire car (Toyota RAV4) until the replacement arrives sometime in the next couple of weeks.

As can be seen by the attached pictures this is no ordinary Battery that you will get from Halfords and I have no indication of the cost of replacement as it is being dealt with under warranty.

I believe the engine is started using power from the main traction Battery, this unit is used to start and maintain the electronics of the hybrid system so it is not “stressed” with major starting current drains so how it can develop a sick cell remains a mystery.

Steve44 · April 7, 2016

The symptoms you describe a couple of other members had on this forum and it was diagnosed as loose Battery terminal connections on the 12v Battery located in the boot, or a faulty 12v Battery.

The 12v Battery is in the boot and is a small motorcycle size and should be a standard relatively non expensive model available from Lexus.

Its highly unlikely to be a failure in the hybrid system or a faulty traction Battery.

I'd get a second opinion from another dealer.

capese21 · April 7, 2016

My car did the same exhibiting the same symptoms as you describe. It reminded me of an electronic game I had as a kid which went haywire when the batteries were running low!!

I had to call the AA who jump started it through the terminal in the fuse box. I checked the Battery terminals in the boot and tightened them up although they were not particularly loose. It has not done it since.

The Battery is a 005L available from many suppliers for around £50 delivered next day.

https://www.tayna.co.uk/S4-024-Bosch-Car-Battery-Type-005L-S4024-P9715.html

The traction batteries are under the boot floor not the bonnet!!

Ed

ganzoom · April 8, 2016

10 hours ago, valanade said:

Symptoms seen were:

Door mirrors unfold sluggishly.

On plugging in seat belt Memory Seat and/or Steering Wheel sluggish or fails to reset to Drivers Memory position

On pressing Power button, hybrid system ready light doesn’t come on and warning alarm sounds followed by message on dashboard saying “Hybrid system failed to start, Select P”

Car is already in Park (P)

The above symptoms appear randomly but are consistent if car is not used over a weekend or after about 15 mins listening to the radio with the power mode selected to Accessory.

On it failing more regularly I measured the 12V battery voltage at the starting connection in the fuse box which read 10.2V DC.

Once I managed to get the hybrid system to start then the 12V system voltage was steady at 14.4V irrespective of whether the engine was running or stopped. Believe that once the hybrid system starts the 12V system is maintained from the main traction battery.

On taking the car in for service (2years, 15000 miles) the fault has been diagnosed as a sick cell in the 12V battery.

The quotes from Lexus Plymouth are “it is not possible to break the hybrid system”, “we have never seen a Lexus battery failure”. A replacement unit is not immediately available and is on “back order” (whatever that means) as apparently they don’t fail so am now driving a hire car (Toyota RAV4) until the replacement arrives sometime in the next couple of weeks.

As can be seen by the attached pictures this is no ordinary battery that you will get from Halfords and I have no indication of the cost of replacement as it is being dealt with under warranty.

I believe the engine is started using power from the main traction battery, this unit is used to start and maintain the electronics of the hybrid system so it is not “stressed” with major starting current drains so how it can develop a sick cell remains a mystery.

That silver thing is the inverter not the Battery. You dealer sounds like they have no idea what they are doing (A common problem with ALL main dealers regardless of brand).

Even if it was just a cell failure in the main traction Battery, that cell can be replaced quite easily. I've even seen a DIY guide on the Internet for it.

What does a 'sick cell' in the 12 volt Battery mean?? As mentioned above the 12V Battery is easy to source and replace.

capese21 · April 8, 2016

Quote

What does a 'sick cell' in the 12 volt battery mean?? As mentioned above the 12V battery is easy to source and replace.

IT is probably what the diagnostics computer has said.

In reality the small 12v Battery in the boot has failed.

How it can take over two weeks to source one is beyond me.

More likely they are so ignorant they have confused the 12v Battery for the main traction Battery which isn't even 12v more like 200v!! Take your car to another dealer who understands how the Lexus Hybrid works.

Good luck with it.

Ed

rayaans · April 8, 2016

There's nothing wrong with the hybrid Battery here.

The seat movement, mirror movement etc is all controlled by the 12V Battery in the boot. Put another Battery in and your problems will disappear

pobrown · April 8, 2016

A family member had a similar issue with an RX400h a few years ago. Turned out the 12V Battery didn't have enough power for some reason and the Hybrid system refused to start as a result. Once the 12V Battery was replaced, problem went away and never reappeared.

It appears to be common on many hybrids. If you look at the Toyota forums for Prius and Auris owners, quite a few have had their 12V batteries replaced. I'm told that the hybrid cars use smaller 12V batteries than regular cars so they have a tendency to run out if the car is not used for a while (this Battery keeps the alarm and central locking powered up).

DanD · April 8, 2016

'sick cell' in the 12 volt Battery

Says it all. Nothing wrong with the Hybrid system.

I had a similar problem with previous RX400h... you just need a new Battery.

... after about 15 mins listening to the radio with the power mode selected to Accessory.

As a rule, NEVER, EVER listen to the radio with power mode selected to Accessory, otherwise the problem will keep recurring. ALWAYS make sure the system is in READY mode and the car in P (not Neutral).

DJP · April 8, 2016

2 minutes ago, DanD said:

'sick cell' in the 12 volt battery

Says it all. Nothing wrong with the Hybrid system.

I had a similar problem with previous RX400h... you just need a new battery.

... after about 15 mins listening to the radio with the power mode selected to Accessory.

As a rule, NEVER, EVER listen to the radio with power mode selected to Accessory, otherwise the problem will keep recurring. ALWAYS make sure the system is in READY mode and the car in P (not Neutral).

When should the power mode be Accessory?

capese21 · April 8, 2016

6 minutes ago, DJP said:

When should the power mode be Accessory?

I would have though when sitting waiting for someone with the radio on. The Battery is rated at 50Ah so actually not that small a capacity. The AA man also said to me to not use accessory and just let the engine cycle on & off. Maybe the current draw from the electronics high? I might go out and measure it!!

DanD · April 8, 2016

When should the power mode be Accessory?

I only use it to open/close windows or open the boot (RX has power boot, so not sure whether this applies to the IS), folding the mirrors, wipe the windscreen clean etc... while waiting for someone.

valanade · April 8, 2016

Thanks for the inputs, as I said in my original post the fault was the hybrid system not being able to go through its start sequence to give the Green Ready indication which is powered by the 12V Battery.

I didn't realise that the 12V Battery was in the boot so thanks for that info, I will check out the boot when I get the car back.

In the meantime I have bought a small jump starter pack which was recommended to me by a friend in the MG Owners Club.

At £30 it will be handy to have for the Lexus and my MGs as apparently if fully charged it will start a 3.5 lite petrol or 2.5 litre diesel engine 20 times which is incredible for something not much bigger that my mobile phone!!

http://www.amazon.co.uk/8000mAh-Starter-Current-Emergency-Ultra-bright/dp/B012SXUK24/ref=sr_1_1?ie=UTF8&qid=1460134374&sr=8-1&keywords=annke+jump+starter

capese21 · April 8, 2016

Quote

Thanks for the inputs, as I said in my original post the fault was the hybrid system not being able to go through its start sequence to give the Green Ready indication which is powered by the 12V battery.

The Hybrid will not activate if the 12v Battery is not charged. When the AA man jumped started mine he put his clamp meter on it & the hybrid was charging the 12v Battery at 40 amps for a while!!

Your car will be fixed by the time you get it back!! I would not be best pleased if my dealer took 2 weeks to source a Battery!! They sound clueless.

Good luck with it,

Ed

wh05apk · April 8, 2016

I had the same issue on mine last year, and again the Battery was on back order, but they managed to source one in 4-5 days, under warranty.

rayaans · April 8, 2016

My IS turned itself off after 15 mins of listening to music on accessory mode. Displayed something on the screen next to the F Sport dial about power saving

DJP · April 9, 2016

9 hours ago, rayaans said:

My IS turned itself off after 15 mins of listening to music on accessory mode. Displayed something on the screen next to the F Sport dial about power saving

Mine did too (so does the NX). As part of Dad's Taxi's I am often sat at a train station waiting for 10 mins or so and happily have power set to Accessory. I would have thought that's exactly the right mode to be in. Obviously I haven't RTFM though

C Mclean · April 9, 2016

44 minutes ago, DJP said:

Mine did too (so does the NX). As part of Dad's Taxi's I am often sat at a train station waiting for 10 mins or so and happily have power set to Accessory. I would have thought that's exactly the right mode to be in. Obviously I haven't RTFM though

Normal for the Accessory function to switch off, there must be a timer built into the system to protect the 12v capacity.

bluenose1940 · April 9, 2016

4 minutes ago, C Mclean said:

Normal for the Accessory function to switch off, there must be a timer built into the system to protect the 12v capacity.

I was sat in my wife's Toyota Yaris yesterday and that happened to me too. Another interesting thing happened too. I was sat in her car whilst she was in the vet's surgery and the phone started to ring, I then heard my son chatting to his mum, I couldn't hear her speaking though, I was then frantically looking around the car to see where she had put her phone but she had had it with her all the time! Am I right in thinking that there was obviously a very strong Bluetooth signal.

DJP · April 9, 2016

3 hours ago, bluenose1940 said:

I was sat in my wife's Toyota Yaris yesterday and that happened to me too. Another interesting thing happened too. I was sat in her car whilst she was in the vet's surgery and the phone started to ring, I then heard my son chatting to his mum, I couldn't hear her speaking though, I was then frantically looking around the car to see where she had put her phone but she had had it with her all the time! Am I right in thinking that there was obviously a very strong bluetooth signal.

Yes although did your wife hear your son? If voice came through the car speakers I doubt it would also have done so on the phone. I'm pretty sure it's one or the other.

bluenose1940 · April 9, 2016

2 hours ago, DJP said:

Yes although did your wife hear your son? If voice came through the car speakers I doubt it would also have done so on the phone. I'm pretty sure it's one or the other.

What actually happened was, my wife took our sons dog to the vet and whilst she was in the surgery she had to call him on her mobile phone to clarify something and, I was sat in her Yaris out in the car park and I then heard the phone ringing through the in-car system, I then heard my son answer the phone but could not hear what my wife was saying to him.

DanD · April 11, 2016

I doubt your wife would have been able to hear your son through her phone: if a Bluetooth connection is made, the audio is routed to the car system and the phone speaker disabled in the process.

Bluetooth range can be up to 10 meters.

bluenose1940 · April 11, 2016

1 hour ago, DanD said:

I doubt your wife would have been able to hear your son through her phone: if a Bluetooth connection is made, the audio is routed to the car system and the phone speaker disabled in the process.

Bluetooth range can be up to 10 meters.

My wife rang our son from within the vets surgery and was chatting to him and I heard my son answer the phone and I was sat in the car and it was definitely more than ten metres