wayman28

Newbie question - I'm trying to figure out which fuse(s) to pull to reset the ECU in my 2009 LS 460. I've read that this is preferable to pulling the negative terminal of the battery because your settings don't get lost.

I've looked through the owners manual and it's not clear to me which fuse to pull for the ECU reset. There is fuse #4 in the fuse box below the steering wheel which is a 5A fuse that the manual says controls the "Main Body ECU" but I'm not sure if this is the right one.

Can someone confirm what fuse(s) need to be pulled to reset the ECU? Do I have the right one? Thanks.

SBlexus

I don't think you lose all your memory when you disconnect your negative cable.

wayman28

From what I've read here you lose your trip memory, radio presets and seat position settings when detaching the negative battery cable. Pulling a fuse seems simpler....if I can zero in on the correct fuse.

roadfrog

All the ECU and fuel injection fuses are located under the hood on the passenger side. Underneath the box lid, the fuses list what is what. Pull all the fuses that refer to an ecu and injection. There is a total of about 6 or 7 fuses to pull. Also, leave them pulled for about 15 mins to allow a reset.

wayman28

Thanks roadfrog. I got impatient and just disconnected the negative battery terminal for an hour. That should have reset the ECU. Thanks again.

roadfrog

No worries, but fyi... disconnecting the battery on any modern vehicle will NOT reset the ECU. Sorta like a computer at home...built in memory backup.

Tee

FYI only takes 30 mins to reset the ECU after disconnecting the neg terminal.

wayman28

So wait, are you saying the only way to reset the ECU is to pull the fuses? If so why do so many threads here say disconnecting the negative lead to the battery will reset the ECU in the LS 460? I just want to make sure I got it right. Thanks.