RX400h locks, mirrors, windows and power door not working after flat 12v battery

[wiccan2]

Hi all,

I've just bought a used RX400h and after getting out home the 12v Battery has died. The seller has now fitted a new one and the car starts and drives again but I am having issues with some of the electrics.

I am unable to adjust the mirrors, open any passenger windows from the drivers controls, lock the doors from the drivers controls (passenger side switch does work for this though), and open the rear power door either with the button on the dash or manually from outside.

All of this was working before the Battery went dead.

I am now also seeing check hybrid/VSC errors on my dash with a master warning light lit also.

Other electronics such as the entertainment system, seats and internal lights seem to be working fine.

The seller managed to initialise the windows and get those working but this had stopped working the next time I went to the car a couple of hours later.

Is there anything I can do to resolve these issues?

 

 

 

[NemesisUK]

1 hour ago, wiccan2 said:

Is there anything I can do to resolve these issues?

 

If this was a trade sale, take it back to the dealer and get them to sort it.

If a private sale, perhaps a local auto-electrician can help. Failing that take it to a Lexus dealership or independent and get the error codes read

[Bluemarlin]

Not sure how it works on the 400h, but check the manual for menu settings,  and see if they're all set to do as you want with windows/doors/mirrors etc, just to make sure it's not a settings issue.

As Peter says though, if it was bought from a dealer get them to sort the warning lights and other issues.

[Spacewagon52]

I had the same issues when my Battery was changed by Lexus. The rear hatch would not open.

Check your handbook. there are procedures you need to follow to reset doors and window operation. Sorry can't remember the procedure but it is something to do with the key fob. My advice, if you can't find out in the handbook, is go to a friendly Lexus dealer. The receptionist sorted mine out as she knew all the tricks/procedures.

[wiccan2]

The car was bought from a dealer who is coming over tonight with an OBD diagnostics tool to read the codes.

 

In the mean time I've got my own OBD scanner working and I have multiple U0146 codes. This LED me to the following thread where someone is having the exact same issues but there was no resolution: 

The full set of codes I read were:

============1==============
U0146
Raw code: C146
ECU: 7EA
Status: Confirmed
OBDII: Data bus, gateway A - no communication

============2==============
C1241
Raw code: 5241
ECU: ABS control unit #2
Status: Confirmed
Lexus: IG Power Source Circuit (MR, Cel.)

============3==============
C1310
Raw code: 5310
ECU: ABS control unit #2
Status: Confirmed

============4==============
U0146
Raw code: C146
ECU: Hybrid engine system
Status: Confirmed
OBDII: Data bus, gateway A - no communication

============5==============
U0146
Raw code: C146
ECU: Motor generator
Status: Confirmed
OBDII: Data bus, gateway A - no communication

 

I will see what the dealer says tonight and push for him to get an auto-electrician or Lexus to take a look.

 

 

 

 

[welland]

On 2/1/2023 at 7:50 PM, wiccan2 said:

Hi all,

I've just bought a used RX400h and after getting out home the 12v Battery has died. The seller has now fitted a new one and the car starts and drives again but I am having issues with some of the electrics.

I am unable to adjust the mirrors, open any passenger windows from the drivers controls, lock the doors from the drivers controls (passenger side switch does work for this though), and open the rear power door either with the button on the dash or manually from outside.

All of this was working before the Battery went dead.

I am now also seeing check hybrid/VSC errors on my dash with a master warning light lit also.

Other electronics such as the entertainment system, seats and internal lights 

 

 

My Battery went flat on my rx400h last week. After I recharged it, I also had check Hybrid  and vac when I started it.  After 5 cycles of stop and start  the messages disappeared.   I don't know if this is reproducible,  but a week later the messages have not returned.  

[Herbie]

11 hours ago, welland said:

After 5 cycles of stop and start  the messages disappeared.   I don't know if this is reproducible,  but a week later the messages have not returned.  

I think that they are still stored as 'Historic' codes.

[Irishman]

I had similar issue with my windows and rear door in my 2007 model last week as well and it was a very easy fix. 

For the windows, go to the individual window control and open the window all the way down and then close it and keep the button held in the up position for a couple of extra seconds. It should then work from the drivers door controls.

For the rear door, lock the car using the actual key in the drivers door lock. Remove key for a couple of seconds then open car again with the key. Leave key in the lock and again turn it to open the car (which is already open), you can now open the rear door by hand and when you close it you will be able to open it from interior button as well.

Hope this helps, it scares me when something goes wrong with my Lexus as I automatically think its going to cost thousands to fix. Then when I find the usually very simple fix it restores my faith and confidence and I give the old girl a good clean inside and outside and appreciate the style and comfort even more.

 

[wiccan2]

It's all fixed.

 

The dealer was about to book the car in with an auto electrician on Saturday but when I started it in the morning the errors had gone away and everything was working again with no need to do any initialisations. It's been going great since 

 

The dealer said that on the morning I bought the car there was a bit of condensation. Only thing we can think is this got into the fuse box and eventually dried out. We did read a code for CAN bus short to positive, so that seems to back up the thinking.

 

Thanks all for the help.

[Irishman]

16 hours ago, wiccan2 said:

It's all fixed.

 

The dealer was about to book the car in with an auto electrician on Saturday but when I started it in the morning the errors had gone away and everything was working again with no need to do any initialisations. It's been going great since 

 

The dealer said that on the morning I bought the car there was a bit of condensation. Only thing we can think is this got into the fuse box and eventually dried out. We did read a code for CAN bus short to positive, so that seems to back up the thinking.

 

Thanks all for the help.

Because you had condensation you should check in the boot under the black plastic tray nearest the bumper (two plastic pins hold it in place) for signs of water ingress in each corner. It's a common issue that can cause serious problems if left unchecked.

[wiccan2]

On 2/8/2023 at 10:43 AM, Irishman said:

Because you had condensation you should check in the boot under the black plastic tray nearest the bumper (two plastic pins hold it in place) for signs of water ingress in each corner. It's a common issue that can cause serious problems if left unchecked.

Thanks for the tip, I've checked and it looks fine.

 

Just done my first long trip in the car, 240 miles and it ran fine.

[welland]

On 2/5/2023 at 12:26 PM, Herbie said:

I think that they are still stored as 'Historic' codes.

I forget how long historic codes are stored, but from  memory, I think it may be 40 cycles. Does anyone know?

[Russell Wheeler]

https://www.clublexus.com/forums/rx-2nd-gen-2004-2009/855067-power-window-reset.html