SH20

4 warning lights at once. 2007 LS460

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Can you believe 4 warning lights came on today.    PCS (Pre Crash System), this is the rear impact detection system.  VSC  (Vehicle Stability Control),  the Warning Triangle and the Engine management warning light.  All in yellow and came on together.    Car drives fine and interestingly the same 4 lights came on  one week after I bought the car two and a half years ago but went off after 24 hours and never came back on till today.    

Car booked in to the nearest Lexus dealer for initial diagnosis but my  preferred dealer is 105 miles away who advised not to drive the car that sort of distance.  They did say it sounds like the engine management system  has picked up a  fault but it can drag other systems into the mix rather than having 4 individual separate faults.  What a bummer!!!.  I have warranty with Lexus but  I have to wait now 7 days before I can take it in.    Anyone else experienced this??  If so what was diagnosed??

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There are several errors that will light all of those warning lamps - you won't have 4 separate faults.

Did these errors appear when starting the vehicle? If so it could just be low charge in the Battery.

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Never heard of that. I have full Toyota/lexus techstream software for my LS460, it might be worth you investing in the same.

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'Close Encounters...' redux? Was there a bright light in the sky and a whooshing noise overhead?  Usually the electrics pack up when affected by a UFO- you're lucky!

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Colin the warning lights came on at the same time whilst driving.   Not sure what "damage" could be caused by driving with the engine management light on.  Is there any risk anybody?  I want to drive 105 miles to my preferred dealer but I'm getting a sharp intake of breathe when I mention this.   

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Check your fuel tank cap. If it's loose, it will be tripping sensors.

If it's not that, it still probably is a malfunctioning sensor ( o2 sensor most probably)

OBD2 readers are quite cheap and you should buy one to retrieve the code. 

 

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I had all these come on a couple of years ago and it was down to a dodgy 12v Battery, replaced with new Battery and sorted 4BEA1E0D-0F21-46EA-9A0C-C2946DBBD14E.thumb.png.9e447272d42747a8c24726d4cf1d7155.png

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Jami that's spooky, just came off Youtube after typing in LS460   warning lights on.     A few videos popped up showing Toyota vehicles with the Engine management light,  VSC and PCS  warning lights on and all of the videos were about making sure the fuel cap is fully tightened.  I had been for fuel just before the lights came on so in the morning I will be checking the cap.   I remember driving another car which needed a fully sealed fuel system, a Bentley and drove it for 100 miles with the engine management light on only to be told by the dealer I hadn't secured the fuel cap sufficiently.      Cheers Jami,  I'll report back tomorrow to see if it's the cap. 

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Checked for  fuel cap not tightened enough but no change, warning lights still on.   Can someone tell me where the OBD port is on the LS460 please.   A friend of mine has a generic code reader and it may help me identify the fault area/fault codes.

 

Cheers

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It is at the bottom of the steering wheel column trim. If you put your head in the footwell by the pedals and look up you can see it.

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Confirmed today an O2 sensor is at fault after a chap i know plugged in his fault code reader and it read emissions fault and listed an O2 sensor.  He cleared the error code and for the moment the warning lights are all off.  I'm guessing they will reappear soon enough.  At least it points me in the right direction so I just need to get up to Carlisle at my preferred dealer.   I'm hoping this is a part that comes under my warranty. 

Does anyone know if my car has 4 of these sensors, two per bank?

 

Steve

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I had a similar problem on my LS430 (2005). All warning lights came on...red and yellow etc. Cleared the fault codes with my reader, but they appeared again after 50 miles.

Main fault on my reader was an o2 sensor, but my local garage diagnosed a leaking exhaust system. Replaced the section of exhaust and never had the fault code again.

A single problem seems to trigger numerous warning lights.

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Thanks Bob, good to know.   Turns out the code reader didn't specify an O2 sensor, it merely stated emissions error. I'm guessing the code reader was a very basic one but the reader cleared the fault and all lights are off at present.   I have a booking on the 20th at a dealer nearby but have no confidence in the dealer who seem more interested in making sure the investigation charges are met by me.  My preferred dealer, 105 miles away,  is only interested in helping me get to the bottom of the fault.  They told me over the phone the 460 has four  O2  sensors,  each bank has two, one before the cat and one after the cat. 

Feels like being between a rock and a hard place at present.  I guess the easiest thing to do is travel 5 miles to my local dealer and at least get them to check out the car and see where I go from there.  

   

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With the fault cleared they may not find any issue. Do you know what code it was? There are at least 10 different codes relating to the O2 sensors and emissions.

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Thanks Colin, didn't realise there could be so many codes Re: O2 sensors.   The code reader machine was one of those that maybe a lot of technicians have in their tool box, a very basic generic hand held unit that points you in the right direction rather than the dealer's reader that is specific to Lexus models.  The only word that came up was emissions and nothing else.    It was the garage who said it was likely to be an O2 sensor.   

Anyway my choice is to go 5 miles to a Lexus dealer I don't trust or risk 105 miles while the lights are off and go back to my dealer who services/MOT  it annually and is just the best at customer care.  The lights will probably come back on at some point. 

Maybe Colin you know what happens when a fault message/code is cleared, does that mean the fault is still  a fault but the lights are off or has it somehow reset the system to operate normally.    

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If the fault remains that light will come back on again. For a hard fault it will come on straight away. If it is an intermittent fault or one that is related to Cat efficiency, it may take a while before light comes back on.

If the light comes back on again and it is O2 sensor / emissions related then I'd say it would be safe to drive 100 miles to your preferred dealer.

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That's very useful Colin.  The car started up normally today, no warning lights.   May I ask another question please.    Does the car store error codes or warnings in a memory of some sort so a dealer can see what the history is on recent fault codes.   If I get to Carlisle and no lights come on I guess they won't be any the wiser if there is no record to view in stored error codes.    If a dealer can view the  history of fault codes it must make it easier to replace a part etc.

Thanks again Colin.

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7 minutes ago, SH20 said:

That's very useful Colin.  The car started up normally today, no warning lights.   May I ask another question please.    Does the car store error codes or warnings in a memory of some sort so a dealer can see what the history is on recent fault codes.   If I get to Carlisle and no lights come on I guess they won't be any the wiser if there is no record to view in stored error codes.    If a dealer can view the  history of fault codes it must make it easier to replace a part etc.

Thanks again Colin.

It obviously stores any current faults, and it also stores freeze frame data - what the vehicle/engine was doing at the time of the fault occurring. Some faults will clear by themselves, the light will go out, however the ECU will still keep a record.

It stores codes unless they are cleared by disconnecting the Battery or using a code reader to clear them. 

 

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Thanks Colin, very grateful for all this assistance.   If I tell you that the chap who connected his generic code reader and witnessed the word emissions on his screen then cleared the error warning which turned the 4 warning lights off.    The Battery was not disconnected but has  he removed all the history now or will the car still retain some data for the Lexus Garage to read early next week?.

About an hour ago the service manager of Lexus Carlisle rang me to discuss a date for a loan car,  can you believe it,  at 3pm on a Saturday afternoon a dealer contacts me to help me out with a loan car.  Just great attention to customer service.   Anyway he gave me some background on fault sequencing and said it's a bit like 3 strikes and your out.  He said the car was actively monitoring the fault in the background on two previous occasions without me knowing anything about it but didn't  activate warning lights.  The system then does a third check  and on the third occasion basically says enough already and puts the warning light on, advising the driver to contact a dealer on the info panel between the speedo and Rev counter.  

Very clever of course but I'm now hoping the dealer will still be able to read something when they plug their own device in the OBD port.  Do you think they will? 

Cheers Colin    

 

 

   

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It is safe to assume that all the history would have been removed. You are best to wait and see if the fault re-occurs.

Depending on the fault, the warning light can come on at the first instance of an error, second (two trip logic) or on the third strike (three trip logic). Certain error conditions are only tested for periodically, when certain conditions are met. Here is an example of how one type of emissions fault is detected:

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For this type of issue, when efficiency is just starting to drop, it will only be detected intermittently. After clearing the error you may go two or more weeks before you get a warning light again. Hard faults on the other hand are detected straight away and when cleared will immediately reappear.

 

At this point in time we are just speculating. I'd personally wait until you get another warning - it has been know for a spurious error to occur that never repeats. If there is a problem then you will get another warning at some point. If you take it to a dealer now they will spend time, and your money, trying to recreate an issue that they may not be able to.

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My code reader gave the following info....Code P0430  Catalyst System Efficiency below Threshold ( bank 2) which told me that the rear O2 sensor on the offside exhaust was detecting a problem in the exhaust gases after passing through the cat. The visual inspection at my local garage found a leak in the rear exhaust section. Got the leaking section replaced and fault code has never returned. The cat was not at fault but the leak was causing the problem and triggering all the warning lights on dash.

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1 hour ago, bobjol said:

My code reader gave the following info....Code P0430  Catalyst System Efficiency below Threshold ( bank 2) which told me that the rear O2 sensor on the offside exhaust was detecting a problem in the exhaust gases after passing through the cat. The visual inspection at my local garage found a leak in the rear exhaust section. Got the leaking section replaced and fault code has never returned. The cat was not at fault but the leak was causing the problem and triggering all the warning lights on dash.

Yes, that is the most common cause. The trouble area section of the example I posted lists the possible causes in priority of investigation.

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Wow, I feel I am in the company of scientists after reading Colin's and Bob's last posts.   Goes to show how advanced engines have become and yet we all just take it for granted,  turn a key and go.    Fantastic insight into what is chemical Engineering really. 

Thanks guys.  I think I will go back to Carlisle where I feel more confident in getting some real assistance.  

  

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Just a line to say my preferred dealer checked the car today and there was no fault code history in the vehicle's memory as per member's posts who correctly stated any code cleared was likely to clear the history.   Car behaved normally for the 230 miles round trip but at least I feel confident that a true report was given to me and there was no charge unlike my local dealer who wanted £120 to plug the car in.

Bought a code reader off e bay which is a step up from some of the cheaper generic models and lists manufacturer specific codes depending on the make etc.  Next time any lights come on I will at least be able to see what parts are potentially giving cause for concern.    

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