Idle-Stop not working ... cold weather or fault ?

[guest6112]

The car is controlled by several computers, you are no longer master of the cars controls. The knobs and switches only ask a computer to carry out your request. For various reasons it might refuse, low battery is the obvious one as the computers will prioritise essential functions. The stop start, climate control, auto lights, auto wipers, and wiper / lights link are good examples of the car deciding what is best regardless of what you the driver thinks.

[guest6112]

Another thought, there are fault lights on many of the cars systems, so the instrument panel will light up like a Christmas tree if the car thinks it is broken. Some more car thinks it knows best ones that the driver has little or no control over are city braking, anti skid, traction control, hill start assist, and abs. The engine ecu monitors the engine and optimises its operation many times a second, people don't complain about that. :-)

[guest6112]

Don't any of you computer experts disagree with my version of events?  :-)

[guest6112]

I have just stumbled across this, it may help the people puzzled by their cars electrical antics. I have no idea if Honda uses this technology but it is an indication of the way things are going. It covers stop start.

http://www.batterypoweronline.com/main/articles/battery-management-with-an-intelligent-battery-sensor-is-vital-to-the-success-of-future-automotive-designs/

[guest6112]

Argggh, having just looked there is a small black plastic box on the Jazz battery negative post with three thin wires disappearing into the wiring loom, I now wonder if it is one of these IBS devices.

[andruec]

I now wonder if it is one of these IBS devices.

Irritable Bowel Syndrome?

 

[guest6112]

In some peoples case it is Irritating Battery System. :-)

[culzean]

I would like to know the effect of stop-start on turbo engines,  where turbo can be damaged if not cooled by spooling down,  if you come from speed to a stop in traffic and engine cuts out straight away heat transfers from 'hot' side into bearings, cooking the oil.  Also affect of stop start on bearing life - if bearings keep losing their pressurised oil supply which keeps the metal surfaces apart, I know car makers say they have new materials in the bearings but don't know how well proven they are in real life service.

[guest6112]

I think the introduction of fully synthetic oils used in most cars these days have solved heat related turbo issues, unless you are driving a fully laden car and caravan up a mountain and stop to admire the view at the top. I have never seen a car with a turbo problem in a motorway service area or anywhere else. I drove them (admittedly diesels) for over 30 years without a problem or any cool down. Is turbo failure a big problem in petrol cars?

[ColinB]

Is turbo failure a big problem in petrol cars?

Not really a problem for the Jazz 

Getting back to the original posting, I started this thread because I was noticing odd behaviour from my car's Idle-Stop (I/S) system and wondered why that might be. I'm now seeing it back to normal again. So same car, same driver, same driving style, same routes, same traffic lights, and the engine now stops when I expect it to. There's been no system reset, or removal/replacement of battery connections, or additional battery charging. The obvious variable still seems to be the ambient temperature, it's now nearly 10 degrees warmer than previously.

The handbook mentions various temperature-related factors that may prevent I/S operation including esoteric measurements like low battery internal temperature (does that need the IBS mentioned previously ?). I thought that the battery would get warmed just by being in the engine compartment, but maybe not enough. So I'm theorising that the low-battery indication may actually be a symptom of low battery temperature (which may of course show up as low voltage), in much the same way that the A/C indication is actually a symptom of the vent position control being on full screen and is nothing to do with the A/C.

[guest6112]

It's that little black box on your batteries negative terminal. Even if it Is only a sensor. I think you are on a loser trying to outguess a modern cars electronics.

[ColinB]

I think you are on a loser trying to outguess a modern cars electronics.

I disagree. If a computerised machine starts behaving differently to previously, and throws in something that looks like a spurious fault indication as well (i.e. a low battery indication on a fully-charged battery) then that to me is something worth trying to understand. It's called curiosity, and it might conceivably have been an early indication of a fault with the battery or the charging system (that is after all what the handbook suggests). Nor do I agree with your thesis that the computer is always right, and neither it nor its various auxiliary sensors can possibly go wrong. They can and do: no machine - not even a Honda - is that perfect.

We obviously have different opinions about this, and you are of course entitled to yours even if I disagree. So let's agree to respect those opinions and continue to enjoy some lively and informative discussions.

[guest6112]

It was curiosity that led me to the IBS device, if your battery is not charging the warning light should come on or alternatively very soon your car will not start. You will not be left in any doubt.  :-)

[John Ratsey]

It was curiosity that led me to the IBS device, if your battery is not charging the warning light should come on or alternatively very soon your car will not start. You will not be left in any doubt.  :-)

Thanks for that useful link to the IBS. I noted with interest that it monitors the battery temperature as well as the charge / discharge rate. I'm therefore wondering whether Honda have programmed a minimum battery temperature (eg 10C?) into the software. On a very cold day it will take a while for the battery to warm up to the threshold temperature and if the battery is too cold then the system will report low battery when the real problem is cold battery which could explain the behaviour we are seeing. Cars should have thermostatically controlled louvres on the radiator grille to help get the engine compartment up to a suitable working temperature as quickly as possible.

[Downsizer]

Cars should have thermostatically controlled louvres on the radiator grille to help get the engine compartment up to a suitable working temperature as quickly as possible.

Do you remember the days when cars had external muffs to keep the radiator warm when driving in sub-zero temperatures?