Stop/Start & Hold Function

Engine, Exhaust, Drivetrain, ECU Issues and Fixes
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SAC1
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Post by SAC1 »

nsm3 wrote: Thu Jan 17, 2019 6:21 pm Dagenham Dustbins, for the avoidance of any doubt!

:D
and Luton Lumps :lol:
Steve

2020 GTS in Sapphire Blue
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Bigboyrolo
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Post by Bigboyrolo »

Tom 2000 wrote: Fri Nov 30, 2018 9:53 pm There does not seem to be a lot of love on here for Stop/Start.
I find it useful and sometimes annoying.
Generally I find it all very useful.
I really liked St St, on the S (always ON) it seemed much faster than on the SD (always OFF). In the e-Hbrid, if a really fast take off is preferred, just select Sport or Sp+ while stationary, the engine kicks in and away you go. In the Fiat 500 its really slow, so its always off, and stays off all the time without having to reselect it off.
On the eHybrid, on e power, there's usually no engine runnng when stopped anyway and I really like the silence, on e power alone its a pretty fast & smooth take-off. Strangely, brake hold only functions on an incline, unlike the Macan. Will there be a Hybrid Macan in the next few years? Best of all worlds if there is.
Last edited by Bigboyrolo on Fri Jan 18, 2019 9:52 am, edited 1 time in total.
"Every year is getting shorter, never seem to find the time" Pink Floyd.
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Deleted User 1874

Post by Deleted User 1874 »

Bigboyrolo wrote: Thu Jan 17, 2019 7:25 pm Strangely, brake hold only functions on an incline, unlike the Macan.
That's what my 911 was like too. I much prefer activating brake hold with the pedal so you can use it anywhere.
happy days
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Post by happy days »

Peteski wrote: Fri Jan 18, 2019 9:42 am
Bigboyrolo wrote: Thu Jan 17, 2019 7:25 pm Strangely, brake hold only functions on an incline, unlike the Macan.
That's what my 911 was like too. I much prefer activating brake hold with the pedal so you can use it anywhere.
I have a manual 718S and the hold function is possibly the stupidest piece of design I have ever experienced. I had a Golf before the McCann and here's how hold worked. Come up to a set of lights, firm press on the pedal, hold engages, pop it into neutral, SS engages ready until you want to move off again. Depress the clutch, engine starts, release the clutch, hold releases perfectly and you drive off. Brilliant, and to my mind, totally normal and intuitive.

Here's the case in the 718S. Come up to a set of lights, firm press. Nothing. Unless the slope is greater than 5% (which is basically an Alp). If the slope is >5%, hold engages brilliantly. Pop it into neutral to activate SS, and hold releases and the car rolls back into the vehicle behind. I kid you not. Also, hold will only engage on upward slopes. Why?

In order to attempt to replicate the Golf scenario, you come up to a set of lights, stop, fumble about under the dash to find the handbrake switch, engage it (if you can remember if it's up or down), the parking brake engages and when you release the brake pedal pressure, the car clunks backwards a couple of inches making you look like a dick to your passenger. Pop it in neutral, SS engages. After about 10 seconds, the battery voltage drops sufficiently so that SS disengages and the car starts on its own. Scared the bejaysus out of me until I got used to it.

Lights change, engage first gear, release the clutch and drive off. Problem is, the parking brake releases with such a lurch that you again look like a total dick to your passenger.

You folks with your PDKs and the perfect hold function really don't know the stress we manual drivers suffer all in the cause of purist motoring.

:D :D :D
Macan S D
718 S
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goron59
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Post by goron59 »

happy days wrote: Fri Jan 18, 2019 10:05 am

You folks with your PDKs and the perfect hold function really don't know the stress we manual drivers suffer all in the cause of purist motoring.

:D :D :D
Surely, for purist, you'd have a mechanical hand brake lever and you'd do a normal hill start? :)

Electronic parking brake on a manual transmission car is just odd, and the position of the switch on 991 and presumably 718 is just demented.
Used to have 2016 Macan Turbo PHCKCL70
Previously a 2014 Macan Turbo.
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happy days
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Post by happy days »

goron59 wrote: Fri Jan 18, 2019 11:49 am
happy days wrote: Fri Jan 18, 2019 10:05 am

You folks with your PDKs and the perfect hold function really don't know the stress we manual drivers suffer all in the cause of purist motoring.

:D :D :D
Surely, for purist, you'd have a mechanical hand brake lever and you'd do a normal hill start? :)
Of course. Plus an advance/retard lever on the steering wheel.
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Robuk
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Post by Robuk »

Hi Guys,

Regarding stop/start deactivation and brake hold, I have been testing this simple hack for the last 10 months on 2 Mercs, R172 SKL and C-Class coupe both turbo petrol with stop/start and brake hold, I have had no issues, no warnings or EML`s, everything works as it should other than stop/start, brake hold and smart charging. With smart charging and regeneration the driver never knows when the battery is fully charged or only 75% charged ready for any regen that may occure, the problem with this smart charging regime is the driver not knowing the SOC of the battery, example, he/she may leave car with nearly flat 75% charged battery at airport parking for two or three weeks thinking it will start on return, the hack gets rid of these problems. I found the economy was only marginally effected. I have last week purchased a Cayman 981 and am at present testing the charging voltage with sensor connected, once this is concluded I intend to disconnect the sensor and again test charging voltage, I am hopeful the Porsche will respond in the same way the Merc`s did.

The hack : Locate the starter battery, you will see on the black negative lead a small black or grey box attached to the battery lead clamp and a small 2 wire connector, disconnect the plug and tape up the male and female ends, that`s it, give it a try, if not happy just reconnect the plug.
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Pivot
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Post by Pivot »

Robuk wrote:...
The hack : Locate the starter battery, you will see on the black negative lead a small black or grey box attached to the battery lead clamp and a small 2 wire connector, disconnect the plug and tape up the male and female ends, that`s it, give it a try, if not happy just reconnect the plug.
Interesting hack. Are you referring to the main starter battery, or regeneration start/coasting battery?
Current: 911 Carrera T - PPM9RU51
On order: 911 Targa 4S - PPDV8NY4
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