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Hi all, I have 2008 IS250 SEL, recently the boot will not open from the remote or from the button inside the car, I have also checked the valet switch in the glove box, I have just taken it to an auto electrician, who has checked all the wiring and connections including the actuator, but no fault can be found, he seems to think that it could be the ECU, I have got the car back for now, he is going to see if he can find out any further information, I have used this electrician a few times, he is very good (he hasn't even charged me for the checking the circuits today) Can anybody help or know what the issue could be, if it is the ECU, I am guessing it is not going to be cheap!! Thank you in advance

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Definitely check the valet switch is working correctly, not just mechanically but electrically.

Have you changed any customisation features, as remote boot release can be disabled in software?

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13 minutes ago, ColinBarber said:

Definitely check the valet switch is working correctly, not just mechanically but electrically.

Have you changed any customisation features, as remote boot release can be disabled in software?

I believe the auto electrician has checked the valet switch, I haven't changed any features, I did have a problem with the air bag light randomly coming on and off, which turned out to be the knee bag wire on the drivers side (I believe it a common problem in the USA) I went to open the boot a couple of days later and it wouldn't open, I was hoping it was something to do with that, but that isn't the case. 😔😔

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Does the release button on the boot itself work OK? 

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15 minutes ago, steve2006 said:

Does the release button on the boot itself work OK? 

No, can only access the boot by using the key in the lock on the left hand side

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I don’t have the electrical wiring diagram for the IS models (LS400s only) but I found a couple of things.

There is apparently a 20A “Door Fuse” which could cause this and I know you have already mentioned your electrician has checked the actuator but did he actually apply power directly to it as shown in the picture below to confirm it is working?

Given that the boot opens with the key which is a mechanical operation and all 3 electrical methods don’t the item common to them all, apart from the valet switch, is the actuator.

There is also a relay normally mounted on the internal fuse board. When you activate the remote boot release button you should be able to hear a click as the relay energises. Open the boot manually with the key and leave it open then activate the remote button listening for the relay click. 

EAE6E354-278E-4578-BDFE-4E9DCEEEF7F9.png

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12 hours ago, Bongo said:

I went to open the boot a couple of days later and it wouldn't open, I was hoping it was something to do with that, but that isn't the case

Almost certainly related - rare that faults coincidentally develop separately.

There is a lot of wiring that goes from the RHD body ECU passed that area to communication with the other body ECU. Both control the door locks. Worth making sure everything else works - lights, wipers etc. etc. in case a fuse has blown or connector knocked.

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2 hours ago, ColinBarber said:

Almost certainly related - rare that faults coincidentally develop separately.

There is a lot of wiring that goes from the RHD body ECU passed that area to communication with the other body ECU. Both control the door locks. Worth making sure everything else works - lights, wipers etc. etc. in case a fuse has blown or connector knocked.

I have tested everything that I could think of, and as far as I know everything is working, but it is possible I have missed something, as there is a lot of goodies on a Lexus 😁

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4 hours ago, steve2006 said:

I don’t have the electrical wiring diagram for the IS models (LS400s only) but I found a couple of things.

There is apparently a 20A “Door Fuse” which could cause this and I know you have already mentioned your electrician has checked the actuator but did he actually apply power directly to it as shown in the picture below to confirm it is working?

Given that the boot opens with the key which is a mechanical operation and all 3 electrical methods don’t the item common to them all, apart from the valet switch, is the actuator.

There is also a relay normally mounted on the internal fuse board. When you activate the remote boot release button you should be able to hear a click as the relay energises. Open the boot manually with the key and leave it open then activate the remote button listening for the relay click. 

EAE6E354-278E-4578-BDFE-4E9DCEEEF7F9.png

Thank you for that, will certainly give that a go, and will show this to the electrician 

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Ok, update on my boot not opening, took it to another auto electrician, who has managed to narrow the problem down to the valet switch in the glove box, they managed to open the boot using some software via the fob etc, there is a fault either with the valet switch or an ECU, the electrician is unable to fix it, therefore suggesting it is a main dealer job, just gave Toyotatech (Guildford) a ring, although very helpful, he has never come across this before. so, has anybody in the forum had an issue like this, can the valet switch be replaced? need some help on this please, don't really want to go down the main dealer route if I can help it! Thank you in advance Paul

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51 minutes ago, m4rkw said:

Try Russell - http://toyotec.co.uk

Thanks will give him a call

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After 2 auto electricians and a trip to Lex Tech in Southampton, finally the issue is solved and fixed!!

Can anyone guess what the problem was??

Turns out, that one pin had been pulled out of a electrical connector block, we think that when I had the drivers side knee air bag wire fixed, the electrician had accidentally pulled the wire/pin out.

they said, it would have almost impossible to find if it had not been for the Toyota software they use, which enabled them to pinpoint the problem.

The guys at lex Tech were brilliant, they collected and returned my car to my home address, and kept me informed on progress, so if need an independent Lexus garage, give these guys a call.

http://lex-tech.co.uk

Thanks fo all who replied and contributed to this topic.

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