LX470 2006 security system/remote InOp

[Don Taggart]

I've been dealing with some electrical issues with drivers side door controls. I located a bad wire in the bundle that goes to the door. The mechanic said he found the bad wire and also said that there was a bad module found during testing when I picked uo the LX470.. He didn't replace the said module (for unknown reasons) but gave me back the vehicle with working door controls. Sadly COVID hit and I was unable to get it back in for repair.

Here's the issues; the key fob remote no longer performs any remote functions...but starts vehicle. I purchased a replacement key and the Lexus dealer was unable to program the new fob. (It starts and turns off in about three seconds) other things I noticed were no auto lights (lights go off with no delay when vehicle is parked and turned off with key) no delay functions. The AC/Heater works fine, but alway is set to 75 degrees when starting the vehicle. The wipers work on full time settings only.

No dash indicator warning lights, everything looks good.

I checked the security fuses and didn't find anything obvious.

The repair manual has limited info on the BCM so I'm unable to troubleshoot the operation properly.

This seems like one of those problems that most local mechanics would struggle with. The dealer wants a test fee $$$ and doesn't replace wire bundles on older LX470s.

Anyone have a problem like this? Advice? Thanks!

 

[Don Taggart]

 

[Don Taggart]

Anyone else have something like this happen?

 

[Don Taggart]

Still in-op. I tried getting another key and new key fob won't program. (Lexus dealer and locksmith) Original key still starts but I needed to epoxy it together. A family member torqued it into pieces.
Any good troubleshooters out there?

 

[Don Taggart]

 

[Malleus]

@Mauser?

 

[Mauser]

It sounds like possibly your broken wire could have shorted and taken out the BCM. Do you have Techstream? If you are anywhere near central NM? I could check it out.

 

[Don Taggart]

@Mauser?

Thank you. I'm going to remove and replace the BCM.

 

[2001LC]

I'd run a full scan with tech stream. You may find DTC, even without a CEL.

06-07 fob is on different frequency than older 100 series. You must have correct fob.

If your interior overhead lights are out. It may be a fuse in RH junction box (passenger foot wheel). This fuse if for interior lights. It also powers the wireless radio, for the fob.

 

[JJLX470]

Did replacing the BCM work for you? I'm having the same exact issues.
In my case the interior door locks, overhead map lights and key remote functions don't work when the car is turned off, however they do work when the ignition is turned to the acc and on modes. This makes me think it might actually be a relay or ignition switch problem.

My plan is to: 1) check the fuses as recommended above, 2) run TechStream to see if it leads me to a code as recommended above, 3) check the ignition relays because maybe the "power always on" ignition relay is bad, 4) find if there is a ignition related switch that turns power on or off depending on if the key is in the off or acc position 5) check for broken wires as mentioned above, and then 6) test & replace the BCM.

Anybody have any better ideas, methodology or thoughts? Also, can anyone direct me (us) to a resource that indicates locations of various relays?

 

[JJLX470]

Follow-up: It was just a 10A fuse that blew, which powered ECU-2. I replaced that fuse (located on the passenger foot side wall) and all functions came back to the items mentioned in the previous post.

I recently had the steering gear assembly replaced and I think that for some reason that process inadvertently blew the fuse. That's my only guess since it didn't blow the fuse after I replaced it.

 

[Exman63]

Thank you. I'm going to remove and replace the BCM.

Did replacing the BCM work for you? I have the same problems