Hello all. Would anyone know if it's possible to get a new mode programmed on the trip display on the 500. I know you've choices of average speed/average fuel eco/inst fuel eco/distance/etc. But what I'd really like is inst speed (instant speed display).

Does anyone with a technical background think this may be possible. (Just simply a mode that's not been enabled). Or would this require new sensors and tons of reprogramming?

Many thanks in advance for any help.

circolo said:

Hello all. Would anyone know if it's possible to get a new mode programmed on the trip display on the 500. I know you've choices of average speed/average fuel eco/inst fuel eco/distance/etc. But what I'd really like is inst speed (instant speed display).

Does anyone with a technical background think this may be possible. (Just simply a mode that's not been enabled). Or would this require new sensors and tons of reprogramming?

Many thanks in advance for any help.

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The 2nd most outer ring of the instrument cluster already fulfills this purpose.

Not sure how easy it would be to reprogram

The Fiat 500 Sat Nav has an instant speed display that is not dependent on the satnav signal

(The speed info is sent by bluetooth to the satnav by the cars blue&me system).

And then displayed on the satnav screen as a digital readout, so maybe this speed pulse could be used for what you want somehow.

306maxi said:

The 2nd most outer ring of the instrument cluster already fulfills this purpose.

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Well it does sort of, if you want to accept the constantly over reading speed display in modern cars, The 500 Reads anywhere between 3 and 10mph over what it is actually doing, but if you take a direct digital read from the Speed Pulse you get your true speed.

Nothing worse than being stuck in 30 miles of Specs cameras on the M1 behind a 1000 numpties all driving at 45 rather than 50 because they rely on the standard speedo.

flashyphotos said:

Well it does sort of, if you want to accept the constantly over reading speed display in modern cars, The 500 Reads anywhere between 3 and 10mph over what it is actually doing, but if you take a direct digital read from the Speed Pulse you get your true speed.

Nothing worse than being stuck in 30 miles of Specs cameras on the M1 behind a 1000 numpties all driving at 45 rather than 50 because they rely on the standard speedo.

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Well depending on what tyres you've got the speedo will always be out somewhat and your sat nav only averages things out over and isn't to be relied on as being 100% correct either.

306maxi said:

Well depending on what tyres you've got the speedo will always be out somewhat and your sat nav only averages things out over and isn't to be relied on as being 100% correct either.

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The Blue&Me Fiat Satnav does not work like a normal satnav that uses the GPS to generate the speed, the Fiat satnav actually takes the speed pulses from the engine and displays those, hence you get speed and direction readings even when there is no satnav signal, as the car supplies speed and digital giro signals by bluetooth. Making it more accurate.

I'm sorry, I'm not understanding this at all. We're saying that we know the standard speedo is not entirely accurate but we believe something called speed pulses in the engine is going to give us a more reliable speed indicator? Can you explain how this 'speed pulse' works?

flashyphotos said:

The 500 Reads anywhere between 3 and 10mph over what it is actually doing...

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I thought they had to be calibrated to be within 10% (whilst never reading less than the car's true speed)?

Are you admitting to driving at 100mph on a public forum?

flashyphotos said:

Nothing worse than being stuck in 30 miles of Specs cameras on the M1 behind a 1000 numpties all driving at 45 rather than 50 because they rely on the standard speedo.

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Nothing worse?

War, disease, famine, poverty, suffering and homelessness are rife across the world, and we are also in the depths of the worst recession in living memory, and the worst thing in your life is having to drive at 45mph in a 50mph limit?

I want your life!

jnoiles said:

I'm sorry, I'm not understanding this at all. We're saying that we know the standard speedo is not entirely accurate but we believe something called speed pulses in the engine is going to give us a more reliable speed indicator? Can you explain how this 'speed pulse' works?

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To me it sounds like someone's been listening to a salesperson

If you want an accurate speedo get a Stack http://www.stackltd.com/prod1.html#dash

End of story

No, Not been listening to a salesperson, just 20 years experience in the field.

A normal Speedo is calibrated within 10% Over NEVER under,

This dates back to cable speedos, but has been held over on the elctronic systems used today which recieve an electronic pulse generated by a pulse sensor on the drive train, this provides speed information to the car in many forms, from the speedo down to the speed sensitive volume on your stereo.

But they still over estimate the speed as it serves several purpous.

GPS generates its speed reading by using the distance / time measurement from the time code signals recieved, this produces a Very accurate speed but with 2 caveats!

1: There is a 1 to 3 second delay on most satnavs between the processing of the info and display
2: The system is not reliable on an incline as car system maps do not take altitude/incline into account, so they will show spot on speed on a flat road but on an incline with read over/under

Hence both are unreliable in their own ways,

BUT the Fiat SatNav Blue&Me unit recieves the speed pulses from the car and displays the TRUE road speed on screen hence removing the errors a normal satnav has by relying on the Sat Time/Distance calculations.

You would get the same true speed reading by plugging an OBD Reader into the diagnostics socket and reading the road speed on the screen

Scrogg said:

I thought they had to be calibrated to be within 10% (whilst never reading less than the car's true speed)?

Are you admitting to driving at 100mph on a public forum?

YES PLENTY OF TIMES - NO SPEED LIMITS WHERE I DRIVE A LOT OF THE TIME!



Nothing worse?

War, disease, famine, poverty, suffering and homelessness are rife across the world, and we are also in the depths of the worst recession in living memory, and the worst thing in your life is having to drive at 45mph in a 50mph limit?

I want your life!

You Can't Have it I am VERY happy with it and am not giving it away

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.

BUT the Fiat SatNav Blue&Me unit recieves the speed pulses from the car and displays the TRUE road speed on screen hence removing the errors a normal satnav has by relying on the Sat Time/Distance calculations.

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Ok, so lets assume that the car has access to these 'speed pulses'. Where is it getting this information from? Is it something the ECU is telling it? Is it something else? If it's calculating based on what the engine is doing and/or what gear you're in then how can it be accurate without knowing what the wheel diameter is? And, in my case, how does it know I haven't changed the diff ratio when I put my lsd in? And what happens in situations of lost traction? I can't see how this speed pulse can be accurate without a wheel sensor and an understanding of the rolling diameter of the wheels? Or ideally an average of the driven and undriven wheels to take into account variable grip conditions?

Do you have any Fiat provided documentation on this function and how it works?

flashyphotos said:

Nothing worse than being stuck in 30 miles of Specs cameras on the M1 behind a 1000 numpties all driving at 45 rather than 50 because they rely on the standard speedo.

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Get out of bed 10 minutes earlier?

Okay, just to explain. I'm a driving instr, and this is our new car for training. The outer white ring speedo is fine from a drivers point of view, but when I'm monitoring someones speed from the passenger seat, it's very difficult to see the speedo until after 50 mph.

However, the little gizmo in the middle of the dials is easier to read from the passenger side. The reason for the question.

It, however, doesn't sound as simple as, say, accessing an engineers (hidden) menu somewhere, and choosing alternative functions. Come to think of it. Is there a hidden/system menu?

jnoiles said:

Ok, so lets assume that the car has access to these 'speed pulses'. Where is it getting this information from? Is it something the ECU is telling it? Is it something else? If it's calculating based on what the engine is doing and/or what gear you're in then how can it be accurate without knowing what the wheel diameter is? And, in my case, how does it know I haven't changed the diff ratio when I put my lsd in? And what happens in situations of lost traction? I can't see how this speed pulse can be accurate without a wheel sensor and an understanding of the rolling diameter of the wheels? Or ideally an average of the driven and undriven wheels to take into account variable grip conditions?

Do you have any Fiat provided documentation on this function and how it works?

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The Speed Pulses are provided by a sensor (VSS) Vehicle Speed Sensor - Also goes under other names,

Here is a link to a training doc that has some info (Sorry Toyota Not Fiat), but if you search VSS applications etc on Google you will find all sorts of interesting (well interesting if you are into sensors etc)

http://www.autoshop101.com/forms/h36.pdf


Its worth at some point borrowing a cheap OBD reader as plugging that in will show you the difference and deliberate under calibration.

flashyphotos said:

Nothing worse than being stuck in 30 miles of Specs cameras on the M1 behind a 1000 numpties all driving at 45 rather than 50 because they rely on the standard speedo.

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It must be difficult being superior to others on the road.

I've been involved in another discussion on another forum, about another car, and the general conclusion was that GPS is inaccurate because GPS measurements are only accurate to about 5m, which means that a speed measured by distance over time is also going to be inaccurate. And the best thing to do is to get your speedo recalibrated everytime you change something that may affect it (such as new tyres, etc). Things like buying new tyres can affect the speed measurement as the radius of new tyres is larger than the equivilant old tyres.

I've never heard of measurement by "speed pulses" in the engine, and am slightly confused as to how taking any measurement from an engine can determine an accurate speed measurement, as the engine just provides the power, which indirectly determines the speed of the vehicle.

I think if a policeman pulled you over for speeding, and you said, "but my speedo said I was ok", you might get away with it. But if you said, "I measure my speed using engine pulses and it said I was ok", I think you'd more likely to get banged up for being a smart ass.

As another guy suggests, just get up 10 minutes earlier.

Besides, if there are 1000 people driving too slowly infront of you, how will your advance measurement of speed help you? Will it turn your car into a DeLorean and make it fly over the top of them, at a precise 50mph?

I think you've entirely missed the point of speed cameras, which is to improve and maintain safety, no matter what the conspiracy theorists say. Anybody wishing to be different from others, and whiz along the road faster than anybody else, just because "they know better", is the one most likely to cause an accident and is the reason why the cameras are installed in the first place. If everybody drove safely, and at similar speeds to everybody else, we would need less of the speed cameras in the first place.

:bang:

JimR123 said:

It must be difficult being superior to others on the road.

I've been involved in another discussion on another forum, about another car, and the general conclusion was that GPS is inaccurate because GPS measurements are only accurate to about 5m, which means that a speed measured by distance over time is also going to be inaccurate. And the best thing to do is to get your speedo recalibrated everytime you change something that may affect it (such as new tyres, etc). Things like buying new tyres can affect the speed measurement as the radius of new tyres is larger than the equivilant old tyres.

I've never heard of measurement by "speed pulses" in the engine, and am slightly confused as to how taking any measurement from an engine can determine an accurate speed measurement, as the engine just provides the power, which indirectly determines the speed of the vehicle.

I think if a policeman pulled you over for speeding, and you said, "but my speedo said I was ok", you might get away with it. But if you said, "I measure my speed using engine pulses and it said I was ok", I think you'd more likely to get banged up for being a smart ass.

As another guy suggests, just get up 10 minutes earlier.

Besides, if there are 1000 people driving too slowly infront of you, how will your advance measurement of speed help you? Will it turn your car into a DeLorean and make it fly over the top of them, at a precise 50mph?

I think you've entirely missed the point of speed cameras, which is to improve and maintain safety, no matter what the conspiracy theorists say. Anybody wishing to be different from others, and whiz along the road faster than anybody else, just because "they know better", is the one most likely to cause an accident and is the reason why the cameras are installed in the first place. If everybody drove safely, and at similar speeds to everybody else, we would need less of the speed cameras in the first place.

:bang:

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here here!!!


one thought- if you know how your gearing is set up- ie how many MPH per 1000RPM, you should be able to work out your road speed from your rev counter.

this information is widely available in car magazines- so if you know that 5th gear is 24 mph/per 1000rpm you should be able to quite accurately calculate the speed you are going based on engine speed...

tho this wont answer the driving instructors original query- how to be able to see the speed of the car better from the passenger seat....


tho again gearing affected by tyre / wheel size