Boot And Fuel Hatch Open When Key Removed.

[James Marsh]

Hello all,

First post so apologies for any poor etiquette here.

I have a Lexus SC430 Soarer Import 2001 (Y-Reg UK)

Not sure if I have a car electrical problem or some issue with the key itself (only have 1 key which is annoying).

On turning the engine off both the boot (trunk) and the petrol hatch open. Somewhat annoying. Any suggestions?

James.

[aquanuke]

Never heard of that fault. Cant think of it being key related. Both keys are the same and then you also have a valet key which does not open the boot and glove box. May be worth asking on clublexus.com alot more US SC430 owners.

[David Breame]

Did anyone ever find an answer to this as mine is doing the same thing 

traced every fuse and earth point no change 

[Stevemak]

Fault is with the gateway ECU which controls both the fuel flap and the boot opener changed a few befor 

[David Breame]

Thanks for reply any idea where it is on the sc 430 so I can have a look and see 

Thanks again dave 

[Neil E]

LHD image but this may help. I didn't think of the gateway ecu and I remember investigating a potential fault on the LS430 gateway a few years ago. 

[David Breame]

Thanks for reply 

found it and ordered a replacement not expensive used at £25

and easy to change so I’ll let you know if it works 

thanks again dave 

 

[genius]

On 2/26/2021 at 8:48 PM, David Breame said:

Thanks for reply 

found it and ordered a replacement not expensive used at £25

and easy to change so I’ll let you know if it works 

thanks again dave 

 

Hi mate Did you solved the problem with gateway ecu?  

 

[David Breame]

No mate not gateway  changed it and still same same fault 

why do you ask are you looking at my car ?

 

[David Breame]

Any more help with this problem would be helpful

tried network gateway Ecu no change 

next thing I’ve looked at could be  body control module 

any body know anything about these or any that can check it out 

or repair 

thanks Dave 

[David Breame]

Hi still looking for help with this anyone out there can shine some light on it

thanks Dave 

[Nigel Dwight]

Hi Lexus Genius's, I know this is an old thread, I need help with the same issue on my SC430, I've been searching ECU's online and the only one I can find which may control the fuel filler door/trunk maybe the Switch, Door Control ECU, part number 84931B  8493124030 

Anyone know where the ECU is located on the car, I'm guessing under the dash some where and would this cure the problem?

[Neil E]

11 hours ago, Nigel Dwight said:

Hi Lexus Genius's, I know this is an old thread, I need help with the same issue on my SC430, I've been searching ECU's online and the only one I can find which may control the fuel filler door/trunk maybe the Switch, Door Control ECU, part number 84931B  8493124030 

Anyone know where the ECU is located on the car, I'm guessing under the dash some where and would this cure the problem?

84931-24030 appears to be the switch below the radio head unit that operates the door so I don't think it will be that.🙂

I thought it was a rare fault but we have seen and chased this or similar on a few cars now and I don't recall anyone reporting that they solved it. The first thing I would do is connect Techstream or a good obd reader to see if there are any stored fault codes. Some of the advanced equipment can send signals to the switches to test operation too.

If you can't easily test for codes, it does sound like a wiring /connection / earth fault to me so I would carefully check the fuses and fuse junction box in the boot and if that looks fine then the wiring to the boot lock/latch and the fuel filler release. I would start by pulling fuse 33, to disconnect the fuel flap and test it. If no change, try fuses 36/37 for the boot lock.   

I think we looked at the following in the past;  

Fuel flap lock

Valet switch connections (glovebox)

Master door lock switch on driver's door.

Gateway ECU

Wiring fault in boot/signs of damp that might cause an issue.

The boot release and fuel flap switch connections

[Nigel Dwight]

Thanks Neil, appreciate the feedback, will take on board what you have mentioned and try and  resolve this problem some how.