Power Back Door (Tailgate) not working on 2010 (Series 3) RX450h

[Walus]

8 hours ago, ColinBarber said:

 

Agreed, more likely is moisture with the recent weather, which could also explain the intermittent nature that some people are experiencing. But why this year rather than previous ones - weather hasn't been that bad. If it is age, I don't recall this being reported before with the oldest 2009 models.

Possibly a combination of the weather and cars not being driven so moisture builds up.

That is a strong possibility for sure. The power lift mechanism is right under the roof rail mounting. It’s ECU is however encapsulated and therefore unlikely to let the water in. Nevertheless this cannot be coincidence as there are too many vehicles of different age affected.

last night I went out to the car to check it once. Unlocked the car and the tailgate would not open. Locked it and unlocked it again, it opened and closed fine 3 times. 

[jean-christophe]

hello everybody, jean-christophe from france nice to meet you.

I'd like to share my experience.

I have the same trouble since 3 years, no PBD working, no lights, no bips, etc...

the two last years, the trouble happened only during winter season, when temperature dropped below 2°/ -0°.

each time, I succeed to fix it by heating the roof compartment with an hair drier and it work all the rest of the year.

this winter we had a cold week early february and the PBD doesn't work again but this time even heating it, unable to fix it.

lexus told me that I have to replace the liftgate motor/ECU.

I think I'am going to do it by myself, it's look like easy.

I will give you some news.

[ChrisM]

could you send that info my way Herbie? Same issue as described above, RX450h 2009 after Lexus Gatwick replaced Battery

thanks

Chris.

[Herbie]

6 minutes ago, ChrisM said:

could you send that info my way Herbie? Same issue as described above, RX450h 2009 after Lexus Gatwick replaced battery

thanks

Chris.

Just sent by PM now Chris

[jean-christophe]

hello herbie

I,d like your infos too if possible

many thanks

[Herbie]

2 hours ago, jean-christophe said:

hello herbie

I,d like your infos too if possible

many thanks

Just sent it to you now by PM Jean-Christophe.

[Vadim]

7 hours ago, jean-christophe said:

hello everybody, jean-christophe from france nice to meet you. ***

I think I'am going to do it by myself, it's look like easy.

Hi Jean-Christophe,

I've recently removed my PBD unit for examination, and managed to test power supply in its socket: the power is there, so no fuses and cables to blame. Haven't tested the signal wires yet, but I bet they are intact. Hence the PBD electronics seem to be dead.

Good luck with the work. To access the PBD unit you don't need to dismantle the entire car, as in the official books, to finally remove the ceiling. It is enough to remove the rear-left part of the trim, covering the triangle window, remove rear left ceiling handle and then you'll be able to pull the ceiling fabric down 10cm to access the screws fixing the PBD unit. 

You'll also need to remove the tailgate white trim to unscrew the PBD lever, but that's easy - held by clips only.

All screws sit very tight with a blue fixing grease, so take a range of small ratchets and 10mm keys. 

Photos:

[Vadim]

I think Lexus is off my list for the next car.

[Vadim]

It would be great to find a microelectronics master who could diagnose and fix the PBD ECU electronics. Chances are there is a single cheap semiconductor burned out. And it might be a 5 min soldering job to replace, once identified.

[Walus]

11 hours ago, Vadim said:

It would be great to find a microelectronics master who could diagnose and fix the PBD ECU electronics. Chances are there is a single cheap semiconductor burned out. And it might be a 5 min soldering job to replace, once identified.

That is what i put my bet on. On the pictures you show, there does not seem to be a cover over the electronic board. That is odd. I would have thought that it should be encapsulated in a plastic cover with a gasket, or did you actually removed it?

[Walus]

Vadim, If the tailgate motor/ECU unit is no good to you anymore and you are willing to ship it to Ireland, I can look at it myself and ask our technician to investigate. I work for an electronic RF manufacturing company - we don't deal with microchips as such but would know were to look for fault. If we are capable of fixing it, we will and I'll ship it back to you. Let me know if that is of interest.

[Vadim]

1 hour ago, Walus said:

On the pictures you show, there does not seem to be a cover over the electronic board.

I opened the cover to check insides. It is held by 3 clips and is not hermetic. The electronic board and components are covered by some water resistant lacquer though. No visual damage or burned elements there.  

[Vadim]

1 hour ago, Walus said:

Vadim, If the tailgate motor/ECU unit is no good to you anymore and you are willing to ship it to Ireland, I can look at it myself and ask our technician to investigate. 

Thank you. I plan to check the signal lines and particularly the PBD off button wiring. If it does not help, I think I’ll post it to you.

[Herbie]

I know it's extremely unlikely to be as simple as this but surely it has to be worth a try.

As I said earlier my power back door is working alright so I can't test this on my own car, so would someone with the problem care to try it and let us know how you go on?

[steveledzep]

7 hours ago, Herbie said:

I know it's extremely unlikely to be as simple as this but surely it has to be worth a try.

As I said earlier my power back door is working alright so I can't test this on my own car, so would someone with the problem care to try it and let us know how you go on?

Done this many times.  Everything still dead.

[Herbie]

2 hours ago, steveledzep said:

Done this many times.  Everything still dead.

Fair enough Steve, just thought I'd ask.

On the second day of my apprenticeship I was introduced to the guy who would be my mentor for the next four years of my life and one of the first things he said to me was, "There's no such thing as a silly question. The only silly questions are the ones not asked."

Here we are, 46 years later, and I've never forgotten that advice.

[jean-christophe]

thank you for your help Vadim

 

I succeed to remove the PBD motor from the ceiling.

Like you, I examinated the printed board, but look OK.

I bought a new PBD at dubai, partsouq (460usd) and I will receive it in few days.

I'll tell you if the new one solve the problem.

[Patrick 450]

Thanks Jean-Christophe, I would be interested to hear if this solves your issue. I'm going to try your hairdryer "fix" tomorrow!

[alitech]

I managed to get into the fuse box today but no idea how to pull out that long blue cover. PBD is fuse number 9 according to the manuals everywhere but is it under the blue strip or somewhere else? I looked at the diagram and not sure how to check if I cant remove the fuse. 

I couldnt find a video anywhere on how to take this out either. Took a pic though.

 

[ColinBarber]

Unfortunately it isn't a cover - the fusible link is a complete unit with the fuse wire built in. As they are used for high current protection, the spade connectors aren't enough on their own and therefore they are sometimes bolted too.

From what I can find on that specific unit, the 60+ Amp elements have holes in them which I assume are for bolts. Therefore you probably have to unbolt the fusebox itself so you can turn it over and unbolt the connections to the fusible link module before it will pull out.

It is probably easier just to check the voltage is getting to the input of the motor/ecu rather than at the fuse itself.

[fezman]

So mine went for service last week and no fault could be found, even though the PBD was not working. I was asked to return it on Wednesday last week for further testing. 

On Tuesday it started working again, and continues to work!! Weird eh! So I rang the dealership and they said no point bringing it in if its working. So I will have to hope it continues to work, or breaks before the warranty runs out in November. 

The above does imply that it is not the PBD motor, nor the fuse. 

[ColinBarber]

It very much sounds like a temperature related thing. Either a poor solder joint or a component that has gone out of temperature tolerance. Easy enough for an electronics engineer to diagnose with a trusty hairdryer and freezer spray but not something Lexus are ever going to fix other than to be happy to sell you a complete £1000 unit and swap it over at £150 an hour.

[Greisingel]

On 2/21/2021 at 2:02 PM, Herbie said:

I'm 90% sure that this'll be the gas struts but before spending any money, check the alignment of the tailgate and make sure the hinges and/or fixing brackets are tight. The tailgate needs to rise straight up, if anything is kocking it out of alignment that could be the problem.

I’ve ordered 2 new gas struts.

I came across an explanation that had me wondering. I don’t know if it is right.

The mechanics of the tail gate are that when the lock releases as you electrically signal to open, the struts do most of the ejection work after lock release.

If the initial ejection is weak and a tipping point of expansion isn’t reached the motor may give up and drop the lid. There is a 16 second motor burnout protection.  The strut may open fully in the end but more slowly and hold reasonably well giving the impression it is good. 

I was sceptical at this.  I thought the motor lifted and dropped the lid. The struts acted only as a damper. If it is correct then it can explain in some cases how seal compromised struts may cause the lid action to cease. 

In my case the lid motor ceased operation entirely working only after some time had elapsed, possibly after the strut gas had in some way altered. 

This may all be nonsense. My Techstream showed no codes for lid. 

[hewsy]

Hi. I am having the same problem with my rx450h.  Power tailgate just stopped working. have checked all fuses and button in glovebox. garage say it may be the tailgate motor and control unit. Please can anyone shed any light on fault. thanks

[alitech]

I just called Lexus after almost giving up with this and they have quoted £180 Plus to just investigate the issue. 50% of that can be used for any remedial work. 

IT STARTS!!!!!! There goes my sanity