Clubjazz - Honda Jazz & HR-V Forums
Honda Jazz Forums => Honda Jazz Mk4 2020 - => Topic started by: Teapotter on October 20, 2021, 11:22:05 AM
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Had my new Mk 4 Jazz two weeks now and getting used to the drive and all associated bells and whistles. This is the third Jazz we’ve had (Mk 1 and 2 previously). Been trying to educate myself by studying the manual but that doesn’t always give you all the answers. I’m not a technophobe but do prefer the basic/simple approach to questions and answers although I realise that this is not always possible especially with technology nowadays. A few queries…I appreciate from a quick look at this Forum that these have most likely been covered previously, but please bear with me and you can’t simply search for ‘B’. Any pointers or advice greatly appreciated.
a. Which is most economical D or B drive, each with or without Econ button On. The manual (P.203) only refers to using B when travelling downhill. The dealer suggested I don’t bother with it, or words to that effect.
b. I too have the clock problem as do many others I see. I have an iPhone 7+. On starting the car the clock shows one hour ahead, but after approximately 5 mins it resets to the correct time.
c. Is there a ‘running-in’ recommendation other than the reference on P.202 to avoid sudden acceleration or full throttle for the first 625 miles. I use the motorway once a week and it would have been good if a maximum speed had been suggested?
d. The first time I drove the car in the dark, 2 warning lights appeared. On stopping the car and examining the manual, one light was telling me that there was an issue with the area around the front wide view camera being covered by dirt etc and being prevented from detecting a vehicle in front, or that it may appear in bad weather or when the ambient conditions are dark (P.92). The other warning light, Safety Support Indicator (Amber) (P.84) explanation is worded very similar to that on P.92. I wiped the windscreen and restarted the car but both lights still appeared, however they both disappeared after about 10 minutes. Exactly the same happened 3 days later, again when driving in the dark.
May this be a fault with the camera or is it something that we just have to live with, being something that happens ‘when it’s dark’ ?
e. Connected to my iPhone, the background on the Screen can be mainly dark when viewing Maps, even in broad daylight. I can only assume that this problem is probably connected to that in d. above, where there is/may be some issue with a light detector which is not functioning correctly?
Pleased to receive any comments
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The only issue I can address is a.
I use "B" in town driving and I've noticed that the regen effect is much more marked, it's almost like one pedal driving. This genuinely does seem to keep the traction battery in a higher state of charge so this must feed through to better fuel economy. I can't speak for the ECON button though - haven't used it.
I would tend to use D for driving that isn't town work.
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Welcome. I hope you're enjoying the new car.
I can comment on some:
a. Also not clear to me. Some on this forum say they use B a lot - but as it's recommended for downhill use, I've not really used it / fear of misusing
b. Not something I've experienced since setting up, but a couple of active threads on this. I think one forum member was booked into the dealer to review (there is a Honda service notice about it?)
c. Will leave to others, not had chance to do a M'way run yet :(
d. With the dark cold, damp mornings, I've noticed the windscreen wide/safety cam gets fogged up, as do the main lights. Normally clears after a mile or so. Those with longer ownership can advise if this is going to be a problem.
e. There is a brightness setting (for both?) daytime and night mode, in the media/maps/entertainment screen which can be found in the settings (touch screen) - and in addition the physical circle brightness button on the dashboard - make sure they're both nudged up.
e.1, I do note the climate control indicators (position etc) are a little fuzzy - not as sharp as it should be?
e.2, Also the backlight on the steering wheel is pretty dim, unless on the highest setting
- anyone else experience this?
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As for a:
I switched from 'D' to 'B' after the first tank. I now only drive in 'B', except on the motorway where I use the ACC (does not work in 'B').
That first full tank gave a measured average consumption of 5.1 l/100 km. = 55.4mpg.
Average consumption dropped to 4.53 l/100 km. (62.4 mpg) after the next 2 tanks and continues to fall (just like the temperature...). https://www.spritmonitor.de/de/detailansicht/1280885.html
An example of a "tourist drive" beginning of October of 257 km (159 miles), not faster than 95 kmh (60 mph): Consumption halfway (the slower part) 3.4 l/100 km. = 83mpg.
(https://www.toyotahybrideforum.nl/download/file.php?id=9665&t=1)
Back home (the faster part) that had risen to 3.6 l/100 km. = 78.5mpg.
(https://www.toyotahybrideforum.nl/download/file.php?id=9666&t=1)
Completed the entire route in 'B'.
Sorry for the long story... from this moment :-X
as for b and e: I don't use an iPhone.
c: The first 625 miles I "behaved myself"... ;)
d: Didn't meet this problem. The car is kept in a garage
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a. Which is most economical D or B drive, each with or without Econ button On.
b. I too have the clock problem
c. Is there a ‘running-in’ recommendation
d. The first time I drove the car in the dark, 2 warning lights appeared.
e. Connected to my iPhone, the background on the Screen can be mainly dark
Pleased to receive any comments
A) the most economical will be with Eco on. Personally I use D mostly and B on windy roads or going down hill. From other hybrids I e driven, light braking only uses the motor so is the same as B anyway.
B) I haven’t had this yet, but will see if the clock changes at the end of the month.
C) most of my first 600 miles were on the motorway. I just used light throttle and backed off a bit if I thought the revs were mooing a bit too high.
D) it might’ve temperature rather than darkness. I’ve had the same messages on an early morning start. The glass in front of the sensor was misting up until the car warmed up.
E) I’ve used the big light button near the dash. I’ve found it’s difficult to get it dark enough for night but also light enough when you are in tunnels/etc. I manually press the button if needed to change.
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A (i). Ever since I did a whole trip in B and liked it, D has been neglected. As already noted, when using B the accelerator pedal almost becomes a speed control, much reducing the need to move between accelerator and brake pedals under mixed driving conditions. I reckon that B should be slightly more economical as it triggers regeneration a little sooner when braking. However, a cautionary note because, once you are used to the automatic deceleration when lifting the accelerator pedal in B, there's the risk of being surprised when this doesn't happen when driving in D.
A (ii). Some people reckon that Econ dumbs the performance but I find the performance plenty livlier enough with Econ emabled. The main effect of Econ is to increase the allowable difference between the target and actual cabin temperatures. This is most noticeable during winter when the engine provides cabin heating and ends up running when it wouldn't in warmer weather. Econ reduces this problem but the most effective way of stopping the engine running excessively is to turn off the heater fan (my standard practice at the start of winter journeys to help the engine get itself hot).
C. It's not the vehicle speed but the engine revs which need a little caution. The engine will be happy cruising at the legal limit. It's also recked than Honda program slightly reduced initial performance into the ECU and the engine becomes more willing after a few thousand miles.
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Many thanks to those who have offered comments etc on the points I raised. All very useful
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I use B all the time now and like its greater braking effect when the throttle is lifted. I believe this delivers better economy - average consumption so far 72.2 mpg. I'm pursuing the clock i-phone issue through my dealer's technical department and will report back. In my case it's more than the clock - there are also Waze and Google Maps Apple Car Play issues. None of these problems exist with my wife's Android phone and Android Auto.
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There have been several topics on here about using 'B' or 'D', there doesn't seem to be a right or wrong it's just a matter of personal preference, I personally only use 'B' going downhill or when slowing down quickly.
I have ECO on all the time, it does make a small difference to economy and the performance is still pretty good.
Don't think there's any 'running in' requirement.
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The one thing that keeps nagging me is, does B mode cause any additional wear ?
I remember back to my advanced driver training where if you changed down a gear to use the gearbox as a brake = fail. My instructor said "brakes are cheaper than gearboxes so stop it"
I'm happy to use B at urban speeds but will there be long term wear issues.
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The one thing that keeps nagging me is, does B mode cause any additional wear ?
I remember back to my advanced driver training where if you changed down a gear to use the gearbox as a brake = fail. My instructor said "brakes are cheaper than gearboxes so stop it"
I would argue that B results in less wear as there's reduced need to switch between accelerator and brake pedals. In D you have to use the brake pedal to tell the car to slow down while in B this automatically happens when pressure on the accelerator pedal is reduced. Effectively, the accelerator pedal becomes the speed pedal.
Using the engine as a brake is another matter. In the e:HEV system this happens automatically if going down a long hill after the battery has become fully charged. Listen carefully and you'll hear the engine start to purr (it took me some months to first detect this happening). The system isn't clever enough to know if there's a lot or only a little downhill remaining.
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Thanks John
What I'm trying to get at, is, with the brake-less deceleration what exactly is causing this deceleration. Is it some form of physical braking that will eventually lead to additional wear somewhere in the innards.
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Thanks John
What I'm trying to get at, is, with the brake-less deceleration what exactly is causing this deceleration. Is it some form of physical braking that will eventually lead to additional wear somewhere in the innards.
In the same way that chemical / electrical energy from a battery is transformed into kinetic energy by the motor using the wonders of electromagnetics, the same happens in reverse. Kinetic energy from the rotation of the wheels is converted into electrical energy and, if possible, stored in the battery as chemical energy. Given kinetic energy is being lost, the wheel rotation speed reduces and the car slows down. In some systems, kinetic energy can be transferred to a flywheel system for immediate reuse before being stored in a battery. I think that is how KERS worked in Formula 1 cars originally. Not sure if it still does.
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Thanks John
What I'm trying to get at, is, with the brake-less deceleration what exactly is causing this deceleration. Is it some form of physical braking that will eventually lead to additional wear somewhere in the innards.
On the Jazz I think B mode is purely the electric motor so should be ok for wear.
In other hybrids you have the regen gauge so could confirm it, but they left it off the Jazz.
Probably someone with an OBD device plugged in can confirm it.
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A very interesting read and helpful in driving my new Honda jazz ex , thanks all from a newbie :D
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The extra engine braking (and extra charging) in B mode comes from increasing the strength of the electromagnets in the charging system. The engine braking effect is caused by drag from magnetic force.The car is being slowed by powerful magnets!
Its not likely to cause much, if any, extra wear and tear.
When the HV battery is full the electromagnets need to be switched off to prevent overcharging. I think the I,C,E engine takes over the engine braking by compression like a conventional car. You are being slowed by compressed air. (maybe a bit less than normal as the Atkinson cycle has a shorter compression stroke than an Otto cycle engine )
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What; you haven't read and memorised all 681 pages of the online Owners Manual?! :D
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I've skipped through the manuals a few times and I often spot something I wasn't aware of before.
As I understand more about the tech I can skip through various pages and concentrate more on others.
I don't need to scrutinise the fitting a baby seat pages any more, that was decades ago.
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I don't need to scrutinise the fitting a baby seat pages any more, that was decades ago.
We just put the carrycot on the floor behind the front seat.
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The extra engine braking (and extra charging) in B mode comes from increasing the strength of the electromagnets in the charging system. The engine braking effect is caused by drag from magnetic force.The car is being slowed by powerful magnets!
Almost right, but the effect is due to putting a load on the motor, acting as a generator, converging mechanical energy into electrical energy via the effect of moving magnetic fields. Energy transfer.
It's just running the main motor with the power flow reversed, so will cause no more mechanical wear than when running the motor forwards. The other motor is directly connected to the ICE and is mostly run in this generator mode (after starting the engine).
There will be some losses to heat due to inefficiencies, of course. When the energy can't be dumped into the battery any more, conventional engine braking is used.
Something similar happens when you press the brake pedal, until the amount of braking force needed requires the use of the real brakes (or something like ABS is needed).