Okay fellers, if any of you have had a similar problem to this, please post up. I have a 2004 LS430 (non-ultra lux) with about 66k miles on the odo. I don't have any after market electrical components installed but I have experienced this electrical problem. The following are some of the symptoms I experienced:

-fuel gauge reads empty (low fuel light on, but tank is full)
-audio unit inop (don't turn on)
-fuel filler lid opens on its own
-trunk release opens on its own (and sometimes locks and unlocks on its own)
-brake lights on at all times (even with ignition off)
-rear license plate lights on (with ignition off)

I checked the wiring diagram service manual this morning and all the above seems to have two common things within the circuit: the luggage room junction block ecu and drivers side juction block ecu. I have not had a chance to look at it yet. I will do so once I finish work today but I wanted to throw this out there 1st and see if any of the fellow Club Lexians had any similar concerns. If so please post it up!!! Thanks.

 

not sure what is exactly wrong but those problems are closely related. well i know a door juntion block ecu can cause multiple problems, but more like: no power door lock, no master window switch, no fuel door switch, no seat memory, no power mirrors. but your problems seem a little differnet. a loose circuit or wire can also cause multiple problems. have you check the codes for the gateway ecu?

 

hello,

try disconecting the neg battery (black) line for an hour.
you will lose radio presets and tank avg, miles from fill up, etc.

 

Not sure if this will help but also check for those bigger fuse....like the big block 60amp kind

 

Thanks guys. I found the problem.

I had water in the left side of the trunk area, which caused the Luggage Room J/B ECU to short. Apparently, when the previous owner had work done on the car (in that general area), the wire harness behind the left side of the rear bumper (going through the trunk) has a rubber weather seal grommet. The grommet was pulled out and NOT plugged in, allowing water to get in. I AM PISSED.

I mean, its one thing for a part to be defective but its another when some ones ****** up affects others. GRRRRRRR!!! Well, I'm gonna see if our local Lexus can warranty it for me (hook up) as I am an employee with the same company.

Wish me luck guys, cause if not it's a $800 part (retail).

 

I kind of had a similar problem. One day im driving and it says Range Approx 107 but the fuel tank light (little yellow light) is on. WTF? i pull up to the first gas station i see, put $20 in there and everything looks okay. Any ideas guys?

 

I am having this issue on my lexus 2004 ls430 full ultra.
no power door lock, no master window switch, no fuel door switch, no seat memory, no power mirrors, no rear seat controll works, no dashboard info wen door is open or trunk no indication at all.
Any body can help wot seems to be the reason of this and wot need to be replaced to solve this issue?

 

Can u ples post a picture of wot u described (of harness behind the left side of the rear bumper (going through the trunk) has a rubber weather seal grommet. ​​​​​​)

 

electrical problem lexus ls 430 does not activate mirrors no fuel gauge no high light

what can i do thanks
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