12v Battery life in Accessory Mode

[TonyHSD]

28 minutes ago, MikeSh said:

This is true. I usually get in quickly, on the edge of the seat, press the brakes and then the start button or the car in ready mode while the booster is still running to minimise that drain. You can hear the booster speed up as the 12V supply kicks in.

That's not true of my MK3. The booster only starts on entry if the car has been idle for hours. Often it just runs for a couple of seconds then, so I think it's just 'natural' leakage of the pressure. Certainly going back to the car a few minutes later doesn't make the booster run.

And why would the high pressure pump need to run to depressurise anyway?

Hi, 

when you unlock the car and open the drivers door the booster pressurises to prepare the car for driving. If you live the door open after 15-30 seconds don’t remember now exact time the booster will start working again, actually it might be a release valve but energy is drawn from the Battery.  To notice that easily you can try for yourself at night with interior light on and watch the light is dimmer while booster is operating. 👌 
You can hear clearly the pressure is released and the rear brakes been used even you can feel it on the parking brake handle or you can see it on the brake callipers, pistons are pushing the pads( apply brake force). The car makes very specific noise like something is knocking onto parking brake cables. 👍 

[Cyker]

2 hours ago, Roy124 said:

Is disabling keyless entry a sticky option or does it reset after switch off? 

It's sticky so you have to use the remote fob to unlock the car, and also hold the fob up to the start button as you press it to turn the car on until you disable it.

 

[Greybeard]

Wow. This thread has been so interesting. I have learnt loads! I'm glad I started it. Thank you all.

[Yugguy1970]

Accessory mode is the equivalent of ignition on in a regular ice car.

You wouldn't/shouldn't sit a car in ignition on for a long time either.

Best to stick in Ready and let it just do its thing.

[Cyker]

What? No! Accessory mode is the equivalent of ACC in a normal car, i.e. position 1 if you have a key.

Ignition in a regular car, i.e. key position 3, is the same as Brake+Start button in button start cars.

 

[TonyHSD]

Start button position one is ACC mode but you can’t operate windows or mirrors or wipers, position two is like ignition ON and all above are operational plus the car get ready for drive booster pressurises dashboard is alight ecu does all checks etc. press brake and push third time and your car will start. , don’t press the brake and push third time and you will turn all modes off and can exit the car for example.

I have read somewhere previously that in case of emergency to switch off ignition while the car is in motion you need to press 5 times the start button, never tried myself though. Does anyone knows if that’s true and have you tried to confirm it’s working? 
 

[Cyker]

I've heard that too - holding the Start button or panic-hammering it should turn the car off, but I don't dare try it! For starters you loose all power steering, and then smeg knows if the steering lock will try to engage or not!

TBH coming from a manual car, I'm just resigned to the fact that if the computer malfunctions and maxes the accelerator like those Fords and french cars had done in the past I am probably going to die horribly as I can't put the car in neutral (HSD doesn't have a real neutral), can't disengage the powertrain from the wheels with the clutch (There isn't one), can't use the brakes (Computer-controlled brake by wire) and can't engage the handbrake (Also computer-controlled).

I suppose at least I can steer the car away from other people and not take everyone else with me, assuming I can overcome the powersteering motor, and even this may also stop being an option if steer-by-wire becomes a common thing...

 

[MikeSh]

2 hours ago, Cyker said:

if the computer malfunctions and maxes the accelerator

My feeling is that in that case it's quite likely to do a HAL and ignore frantic button pressing too ..... 

[Derek.w]

For myself its far more convenient to fit a solar panel this I only disconnect if I am going to use all seats otherwise I just place it on a spare seat.

 

[Cyker]

4 hours ago, MikeSh said:

My feeling is that in that case it's quite likely to do a HAL and ignore frantic button pressing too ..... 

Yeah, hence my resigned to a spectacular death comment  

Although given how strong the car is maybe I'd still survive! It has been proven to be range-rover resistant...  

[Roy124]

14 hours ago, MikeSh said:

My feeling is that in that case it's quite likely to do a HAL and ignore frantic button pressing too ..... 

Can be quite terrifying when the car does its own thing.  I was cruising up the M6 in a Capri at a legal 95 when the car stopped responding to the throttle. 

Revs increased and the car would not slow down.  Going to neutral at least meant I could brake and I was able to move from lane 3 to a convenient slip road.  

The accelerator pedal was flat on the floor.  I managed to get my toe under and that slowed the engine revs. 

There was a garage* just down the road and they fitted a new pedal return spring. Remember when every village had a blacksmith style garage? 

 

[Cyker]

That's the sort of unlikely edge-case I've always been slightly worried about, going from a manual to an autobox; I liked knowing I had 2 ways of totally cutting the engine off from the wheels in an emergency, whereas modern cars completely cut you off from having any direct control, aside from the steering.

But yeah, real mechanics are thin on the ground these days; Too many are really just 'fitters' and don't have the creative skill or motivation to do anything other than use diagnostic reader and parts cannon.

It's a sad skill drain, but the problem is the world has just made it untenable; It's faster and more profitable to replace something than repair it, and this has just been encouraged, and is why we're in this ecological mess in the first place.

Cars, computers, cellphones, all have become increasingly unrepairable, deliberately so in a lot of cases. The fact we have to *fight* for the right to repair our own stuff now just shows how stupid it's become, but not enough people care as they're happier to chuck and replace because it's the path of least resistance.

[TonyHSD]

No worries if your Toyota hybrid develop a fault while you are driving, you will most likely loose only propulsion, but all other controls will remain operational and you will be able to stop safely. The real problem is only the lost of power while in the right lane at busy times., with the smart motorways and the very “smart behaviour “ of many drivers the risk of accident with serious consequences is very high but that applies to all type of cars you drive.
Once when I had “ hybrid system malfunction “ and the car lost any power it was scary experience, luckily I had a chance to pull over on the side grass verge otherwise i don’t want to imagine. When this happened the car simply went into N neutral, there was no power at all but brakes and steering were  working fine. After restarting the car was drivable again. 

My second experience was when the wheel speed sensor gave up, well similar experience to above but that happened on exit of motorway, while I was slowing down in slight regenerative braking on the slip road suddenly a few dashboard warnings appeared, a sound alarm and more warning  starts flashing, the car went off regenerative braking and gave a feeling of loosing the brakes but actually it was only the regen lost and brakes remained fully operational front and rear. There were red lights and yellow warning, I run a quick diagnostic and after I discovered what was wrong I continued  my journey safely although there were no regenerative braking and the car didn’t want to go into ev drive at all , engine was running all the time and Battery was draining faster ( total driving probably 20-30 miles). 
Both ways there was no immediate danger caused by the car like lack of control or anything, but serious risk of accidents caused by other road users, who pay no attention to what is happening around, been aggressive, tailgating, speeding etc. , this is the problem these days, the cars are getting smarter , the drivers are not. 🫥

[IT Troll]

I believe the Toyota hybrids have quite an elaborate fail safe on the braking system which will switch from brake-by-wire to traditional hydraulics in a power failure situation.

But without a mechanical handbrake I guess you don't have that as an option of last resort. Would flicking the parking brake switch do anything in that scenario?

[Cyker]

My main concern is software bugs TBH, as they could prevent any of the mechanical failsafes from working. The problem is the software 'industry' have extremely poor practices that prioritize output over code correctness, and have moved away from a model of iterative exhaustive testing before moving on to the next module to rapid iterative code revisions.

To me, this method of programming is incompatible with safety as it means lots of edge-case bugs will never be found until the code is out in the wild. This change in (I forget the word, attitude? practise? procedure? convention?) is partly why Windows 10 is so much buggier than any previous version of Windows (Even the hated ME!), and is *still* buggy despite all these patches, as every patch seems to introduce new bugs!

The problem is this is infecting the car industry too - Part of the reason they have such a chip shortage crisis is they use *really* old chips, but these have very simple code with less scope to go wrong because they can't do much.

Newer processors are much more powerful, but they encourage code bloat which makes bugs more likely to creep in, esp. with the more modern iterative approach to programming, which the car industry is also moving into from the older slower but safer way of doing things.

As cars become more computerized, easy to diagnose mechanical systems give way to bafflingly complex and mostly incomprehensible code, and I don't mind admitting I'm not entirely happy with this - To paraphrase one of murphy's laws, "To err is human, but to really smeg things up you need a computer."   

I'd feel much better if everything had some sort of mechanical linkage to let me override the computer if it fritzes up, but I'm already running into a taste of these problems with the throttle-by-wire not letting me accelerate because the safety system thinks there is a collision risk and leaves me hanging in the middle of a junction, and the brake-by-wire not providing correct feedback so I overestimate the braking force I'm applying and have to suddenly floor the brake when I realize the car isn't stopping the way the pedal feedback suggests...!

...

Err. *glances at frosty*

Anyway, back on topic!  

...

So yeah, don't use accessory mode on hybrids.  *shuffles away*