oPless

Hi, it seems this is the right place to come for rear door issues!

My story is this;

I put my car into a random local garage for an emergency MOT (a UK annual roadworthiness test) as it was due the same day. It passed!

However the next day I noticed the rear door power tail not working. Now I just thought they might have knocked the secret button I had read about so I wasn't too bothered.


I come to investigate it properly today.

Toggled the button in the glove box, made sure it was "on" as per the manual.

Removed power by disconnecting the 12V battery. Waited a few minutes and reconnected everything. My voltmeter shows a nice 13.8V.

Located the main fusebox in the engine compartment and pulled and checked a number of fuses... I checked a random sample and they were all okay. I have no idea which fuse operates the rear door lift motor.

Phoned the local main dealer and enquired how best I can diagnose the fault myself, as I have tried the things I mentioned above.

Apart from telling me too open the door fully and push the button, and also check the internal courtesy lights in the back, he advised to bring it in for a diagnosis (at least 3 hours because of headliner removal and tracing wires) which seems a bit steep considering these things are all fly by wire.

I did notice the garage had been pressing stuff at random on the nav system and steering wheel to get the odometer values, so I'm thinking it might be a setting in software perhaps ?

The door manually opens easily, the key nor the button on the dash "do" anything, no clicks no beeps.

I'd be open to any suggestions right now as I just don't have the budget right now for an expensive non-essential item to be fixed by the dealer!

matts6887

it sounds like it could be the motor itself that has finally bit the dust so to speak; but its also possible there could be a electrical issue such as faulty wiring etc going to the motor itself which could be causing this.

oPless

That's what the nice chap at the dealership said on the phone. But it's been working well without any weird noises or behaviour before suddenly not working. Hence thinking it was the glovebox button initially. 😂

Margate330

I wouldn't pay for 3 hours of diagnostics before doing some simple tests first since that's probably the appetizer before the bill. lol

Also, I have Power Trunk/Back Door Option and just did a basic operation test.
Simple test- close the Back Door slowly & gently by hand and just lay down the door at it's lowest position.
It should click and then hear & see the door motor pull the Back Door in to it's fully closed position and confirm motor operation and Power Back Door ECU is at least doing something..
PS- Once in the lowed position my door took a light press downward for the click and motor action to work but lifting the trunk(back door) requires the motor to have much more strength and the Back Door struts assist with this effort so they must be good too.

oPless

My thoughts exactly!

In fact I bought a service manual CD from eBay, as it was only a few dollars for a zipfile!

As soon as the rear door is near the bottom of its travels the locking mechanism whirrs and latches the door.

Grabbing the door handle switch unlatches opens the door as normal.

I have an ODBDII adapter somewhere, so I'm going to try and read any error codes. (Also known as DTC - I think?)

My vehicle repair skills are stuck in the pre-odbII age where all you needed to do was fix the choke or blow on the carb

Margate330

Ok this is good since the "Power Door Lock Assembly's" motor sounds like it is working good.
The "Power Back Door Drive Unit" aka back door lifting motor is powered by the same ECU and should confirm your 30A PBD fuse is ok but can check anyway.
.

With tailgate fully open, pressing this button should sound 2 loud beeps before attempting to close- if not the Power Back Door feature may be disabled by the Power Back Door ECU.





Here is why they want to tear out the headliner.
Location of the driving unit & ECU, however many tests can be done at the ECU without removing headliner to get to the driving unit.

oPless

No beeps, hence looking at getting a readout of the codes. Cant find my generic USB ELM327 thing so ordered a Bluetooth one, and another ELM327 dongle.

The service manual mentions an 'intelligent tester' so I'm assuming there's proprietary diagnostics going on somewhere on the CANBUS - is there alternative software to be found that reads these Lexus magic codes that people use here/can recommend?

oPless

So I was attempting to read codes with ODB Fusion and NEXAS NexLink Friday evening, after reading the codes I notice a problem.

The Dashboard after 10-15 mins starts doing a passable imitation of a disco. Turns out my battery was down to 11V (and 7V in the morning), and of course - refuses to start.

Today, after getting help from a neighbour to start the car - the passenger's heated seat is activated, the led is on, but the controls are set to "off".

Battery ordered for Tuesday, and a spare jump battery (a proper 12V one, not the lithium boost packs that double as USB chargers)

It seems that there's some issue with communicating with the other networks (probably the NexLink can't access them) - so I've got a Toyota specific cable on the way.


So faults now are:

• Back door doesn't raise or lower automatically
  • assuming it's gone into a fail-safe mode that is only fixed by a diagnostics program
• Windows don't raise or lower from the drivers console, or long press on key fob
  • I think the fix is to raise and lower them. Not done yet, because faulty battery
• Heated passenger seat, and ignoring controls.
  • Probably needs an ECU reset or a cleared code? - the forums seem to indicate that low power makes various systems unreliable.

I'd love some feedback on my proposed fixes on the above. It's all very frustrating that you'd have to fix these things by going to the main dealer and have them handwave the faults away with a proprietary diagnostics laptop

minoku

I hope this would help.


Part Number: 68910-0E014

oPless

Oddly enough I watched that video an hour or so ago, the motor certainly isn't running (using techstream test mode) - no beeps either.

I'm hoping after getting a new battery that everything will magically work again

Thanks for the part number, I shall ebay that.

Any hints on how to pop the headliner out?

minoku

this girl actually done it by herself. I think you can do it too


I never done that before so I'm not sure. Just find a random video that would help. Hope it helps

oPless

Nice!, I saw a bodywork video where he repairs a bodged together RX330, and it clearly shows how to undo the headliners

... just found it...
Today I got the battery and fitted it!


So faults now are:

• Back door doesn't raise or lower automatically
  • assuming it's gone into a fail-safe mode.
  • No codes raised by the back door ECU, no movement on techstream manual test utility.
  • Lexus want almost £800 including sales tax, looks like an eBay job (under £100 delivered!).

Fixed

• Windows don't raise or lower from the drivers console, or long press on key fob
  • I think the fix is to raise and lower them. It is - confirmed by a super helpful toyota tech.
• Heated passenger seat, and ignoring controls.
  • It seemed to clear itself, weird. The indicator LED still shows as on, but faintly. Not sure what's going on there. But it's not showing any codes, nor is it erroneously heating the seat!