Display/battery problem

[Superduner]

As I've posted elsewhere, I've been having Battery drain issues for the last few weeks on the "little" Battery.  I suspected the 1 year old Toyota Battery was faulty so changed it for a new Bosch.  It drained from 12.8V on the car (after Ctek charging) to 12.1 overnight.

I put in a power plug voltage meter and checked that against a proper multimeter (pretty much spot on).  Today on a run the meter was reading 14.5v (so it was charging), whereas yesterday it was 14v.  When the engine was turned off it quickly went down to 12.5, and after a couple of hours down to 12.2.

So, today I disconnected anything not original Lexus.  OBD dongle, Ctek comfort lead and the Vline audio system.

Now I don't have any display for the Lexus satnav, menu and dest. or reversing camera except a black screen with vertical yellow strips.  Audio, climate and info are ok.  This is all, I guess, something to do with taking out the Vline.

I'm obviously destined to spend some time online with Vline support if that is something to do with the Battery drain (and to be fair they have already offered to change the unit for an unrelated Bluetooth issue), but why the display issue with nothing connected?

Something (or things) strange is going on, but what?  There are no error messages, and the car is running fine.

Edited March 5, 2021 by Superduner
More info

[Fatts]

There is another thread on Battery drain that you may be able to get some tips on the problem 

 

 

[Superduner]

31 minutes ago, Fatts said:

There is another thread on battery drain that you may be able to get some tips on the problem 

I'm on that one already!

 

 

[Herbie]

1 hour ago, Superduner said:

So, today I disconnected anything not original Lexus.  OBD dongle

If you leave the OBD dongle connected all the time, some of these have been proved to drain the Battery.

[ColinBarber]

6 hours ago, Superduner said:

Now I don't have any display for the Lexus satnav, menu and dest. or reversing camera except a black screen with vertical yellow strips.  Audio, climate and info are ok.  This is all, I guess, something to do with taking out the Vline.

Doesn't the Vline cabling pass the video from the infotainment system through Vline unit and on to the screen? Therefore just disconnecting the unit without connecting the infotainment system and screen back directly together again will result in no video being displayed.

[Superduner]

7 hours ago, ColinBarber said:

Doesn't the Vline cabling pass the video from the infotainment system through Vline unit and on to the screen? Therefore just disconnecting the unit without connecting the infotainment system and screen back directly together again will result in no video being displayed.

Exactly.  As I later found out.  I thought, wrongly, that if the Vline wasn't connected it would revert to normal mode.  So I'm going to have to do without the satnav until I've figured out if it is the Vline causing the drain. According to Vline:

"We have different sleep modes for the VLine, the initial sleep mode is around 0.3 Amps and is for around 10 minutes, then goes down to 0.1 Amps, then over the next 24 hours it goes down more until the end of the 24 hours where it completely turns off."

I've had a few minor issues with the Vline, mainly Bluetooth, and they have already offered to replace it, so I'll reassess after the weekend.  Part of that reassessment will be to put a multi meter on the Battery earth to actually measure current drain.  I couldn't do that before as a mate had my good Klein meter.

[Superduner]

12 hours ago, Herbie said:

If you leave the OBD dongle connected all the time, some of these have been proved to drain the battery.

 The OBD Link dongle is specced to draw 2mA, but in my experience it is not good at "waking up" ready to pair with the car.  That that means that I have to go through the whole pairing thing again to make it work with Hybrid Assistant.  My cheapy dongle is much better at "remembering" but as yet I don't know the current draw.

[Superduner]

I've just put a multi meter in line with the disconnected earth cable and the current draw when the car is completely off is 1.2mA.  That's with the Vline disconnected, and the OIBD dongle out.  The reading does not alter much, if any, when they are both connected.  As I understand it, they will both require a small amount of constant current to "remember stuff", along with the Lexus audio system and security system also taking a bit of power even when the audio is off.

The Ctek comfort lead uses 1.7/2.5 mA (it alters with the flashing signal light).

So, does that mean that I'm overthinking this and all is ok and normal?

[Herbie]

A couple of people in the Lexus Owners Club Group on Facebook reckon that the quiescent current draw should be in the official spec sheets for the car but I've never seen it mentioned anywhere, nor would I know how to go about finding it. Maybe a call to a dealer workshop may provide an answer, I don't know.

What I can say after watching many YouTube videos and doing a lot of Googling, is that most people (both professional and hobbyist) seem to say that a figure of about 50mA +/- is considered to be 'normal' for a modern car, with anything much above that indicating the presence of a fault.

Unfortunately, the only way of confirming if this is correct is to find out the manufacturer's official figures.

[Superduner]

Fyi:

Lexus RX 400h Questions - starter battery not holding charge - CarGurus

It's obviously a very well known issue, and one which apparently is not possible to fully fix. 

[Herbie]

1 hour ago, Superduner said:

Fyi:

Lexus RX 400h Questions - starter battery not holding charge - CarGurus

It's obviously a very well known issue, and one which apparently is not possible to fully fix. 

TL:DR - but I wish some of those people knew how to use paragraphs!

It is indeed a very well known issue and has been done to death, to be honest. It's a design 'fault' and could have been avoided by specifying larger capacity batteries, but they didn't so it's just something that we have to be aware of and live with.

[Superduner]

I've ordered a low current amp clamp to avoid the issue of waking up modules when disconnecting the earth lead (and yes, I know that they are not terribly accurate).  Hopefully it will let me let the car go into sleep mode as well before testing

I'm suspecting that the current draw rises dramatically when the key is put to acc, presumably because systems go live waiting for the actual "start".  I can't find any info online about exactly what extra load is placed on the Battery in this state.

The RX400H would be a terrible car for a police stakeout where they sit for hours with the radio on, eating doughnuts.  Villains emerge, Plod tries to start car for the dramatic chase...and nothing.

Still, better than the old Rover 3500s where the hydraulic valves couldn't catch up to the pistons from rest until the pressure built up.  My dad had that happen a long time ago.

[Herbie]

18 minutes ago, Superduner said:

I've ordered a low current amp clamp to avoid the issue of waking up modules when disconnecting the earth lead (and yes, I know that they are not terribly accurate).

It'll depend on which make and model you've ordered but my clamp ammeter is very accurate when measured against the other test gear I have. It's a Uni-T UT210E and I'm well chuffed with it. If I was still actively working I'd have all Fluke gear but couldn't justify the expense now that I'm retired.

23 minutes ago, Superduner said:

I'm suspecting that the current draw rises dramatically when the key is put to acc

Absolutely!

I think the RX400h has the 12V Battery in the engine bay so in order to read it and get an accurate reading you'll need to leave the bonnet up and make sure to short out or tape the alarm switch closed so that the system thinks the bonnet is shut and the alarm can be activated.

Doing it this way will only give you the total current draw. If it's high and a fault is suspected, you'll then have to start looking at individual circuits to find the culprit but don't start pulling fuses and watching for when the current drops because that will start waking up ECUs and other circuits.

Reconnect the Battery as normal, open both front doors and the bonnet for access to fuse boxes (not forgetting to set the locks and door/bonnet switches so that the system thinks the car is locked and can go to sleep) and after an hour or so, start looking for voltage drops across the fuses - highest drop should be the faulty circuit.

[AWF]

The tech who loooks after my 400, 2007 has just done a parastatic drain test on car has reported 0.01mA to 0.04mA when the vehicle sleeps. He also said that when he worked for Toyota he was told anything over 0.05mA indicated a potential fault. 

[Herbie]

2 minutes ago, AWF said:

The tech who loooks after my 400, 2007 has just done a parastatic drain test on car has reported 0.01mA to 0.04mA when the vehicle sleeps. He also said that when he worked for Toyota he was told anything over 0.05mA indicated a potential fault. 

I think you're getting your units mixed up there Alan, because that seems very, very low?

0.05A is 50mA, which most people seem to think is 'normal', but 0.05mA is only 50uA so to consider anything above that as a fault means that there's a lot of faulty cars knocking about 😊