Hi not new to forum but been away for along time
just purchased a2006 sc430 in amethyst pearl with camel interior
small problem when I turn off the ignition both the boot and fuel flap open
any ideas to solve would be gratefully received
thanks dave

 

LOL. This requires detailed review of schematics. Give me a day or so and Ill see if I can find a possible common failure point. But a couple of questions first. does the boot work normally using the key fob? Does it work normally using the switch on the dash? What about the fuel flap? Normal using the switch?

Paul

 

Hi Paul
thanks for reply yes everything works as it should key switches and valet switch
ive taken out all fuses and replaced them with new
removed switches and stripped and cleaned them put on a new battery and did a reset still problem is there
look forward to hearing from you thanks again dave

 

Just a dumb question: what is the boot?

 

I believe he lives in Norfolk England not Norfolk Virginia. Boot is the trunk across the pond.

 

GmanSC

Have you never watched "Wheeler Dealer"?

Dennis

 

Correct in England sorry it’s a different language here I’ll try and remember in future to translate before I post

 

Considering both of those buttons are located right next to each other it sounds like some kind of short at the buttons themselves. Very weird problem. These buttons work correctly when pressed?

 

Thats trunk in European. ;-)

OK. I obviously can't be 100% certain, but the boot and fuel lid both tie into the "Luggage Room J/B ECU", AND the "Driver Side J/B ECU". You said the switches work normally. Im assuming that's both the key fob as well as the swiches on the dash.

Next question, do they open if you switch the key to the ACC position or only when you switch from Ignition/ACC to Off? Do the mirrors, all lamps, hood lock, etc. work normally? To do a proper diagnostic would require an O Scope. But that shouldn't keep you from having a professional diagnostic. Its unlikely you would find this problem using a multimeter.

If I had to make a guess though, I would be looking at a possible problem with the Drivers Side ECU. Maybe a failed component inside that is causing a transient voltage spike when you switch off. But these modules are tied in with sooooo many systems.

First things first. Pull your battery cable. Reset everything. Then reconnect and test EVERYTHING! Every lamp, switch and function you can find. Seat heaters, mirrors cruise control. There might be other issues that you haven't identified yet that could help narrow down which part is failing. You could have something as simple as a poor connection. Then you have to do the opposit. Start pulling fuses. Thats to see if there is another component causing this. But you really dont want to start throwing parts at this. It could get way expensive.

Paul

 

Hi guys
so spent last few days pulling fuses and removing drivers side fuse block
one behind kick panel still can find no faults
but trunk and gas flap still keep opening when I turn ignition switch to acc position and turn engine off
every other item seems to work ok
next thing is to try and find a fuse block to change and see if it’s that
could there be any other j/b that connects to this power line if so where would it be hiding
thanks Dave

 

I don't have the p/n for the ecu's in question but there are replacements available on ebay. Ill check a little later and see if I can find the correct p/n's and see if you can find a replacement at a reasonable price.

Paul

 

disconnect the two switches for the trunk/boot and gas door/flap.
turn ignition to ACC/off

does it still open them?

 

This is sheet one of the schematics I believe are the most relevant. It shows the two switches tied into the Drivers Side JB ECU as well as the ignition switch.

 

The second sheet shows continuation points A and B. This is the connection to the Drivers Side JB ECU as well. Its a complex circuit due to its connection with the ignition circuit and unfortunately, as I stated earlier makes troubleshooting all the more difficult.

 

If there is anything else I can help with, don't hesitate to ask. Heres another picture on the location of the ECU I would investigate first.

There is one odd point that you should check since I believe that you have one installed. The Mirror Retractor Switch. It was not included on U.S. models but is tied directly into the junction block for the fuel and trunk switches on the European models.

​​​​​​​Paul