how does the gear sensor work?

[AJAY]

Thinking about designing a simpler gear indicator than the GI-Pro or similar, using a set of LED lights or an LED light bar.

Does anybody know how the gear position sensor works electrically? Looking at the wiring diagram, there appears to be only three wires

* one wire goes to the engine control module

* one wire appears to tie into the safety interlock (kill switch) with the kickstand sensor and the neutral light

* the last wire (the "sensor" line) appears to connect a line from the engine ECU to a rheostat for each of the 6 gears.

From this drawing (fig 8-14, Fuel Inj Sys Wiring Diagram) in my factory manual (green one, through K04), it looks like the 1st and 2nd gear spots should read about the same resistance (hmm, this must be what the timing retard is about and how an aftermarket TRE fools the ECU. Is this correct?).

Does anybody know a diagnostic test and anticipated results for the gear indicator? As in #1 = 1000 ohms, #2 = 1500 ohms, #3 = 2500 ohms, #4 = 4000 ohms and so on? Or maybe you can pick up a voltage on the sensor line when the ignition is on?

- thanks, AJ

 

[AJAY]

Kept searching on the web and found detailed plans for a nice digital gear indicator for a Suzuki GS500 twin with 6 speed trans. Will bet that it would work on a Busa. Probably too much work to build. Would there be anyplace here to post the PDF file if people were interested?

 

[BusaWhipped]

Yes. Somewhere on the board I have a post about building exactly what you are taking about. Don't have time to search for it before work.

 

[smithabusa]

get with me ill walk you through doing one like this, ill see you the pc board etc if you want to make it easy, i used to make them like this.

only downside is you have to pull the resistors (all 6 of them out of the sensor) and then run another 6 wires in the sensor, each wire will provide a ground while in the corresponding gear, use that ground signal to turn the LED on).

You will have to hardwire a 6.8K resistor at the gps connector and it will work like a standard TRE.

I have the new billet deal and dont sell these anymore but have some parts etc.



here is a video of the one i was making with built in launch and shift light, pretty cool
www.boostbysmith.com/Videos/launch1.wmv

 

[smithabusa]

1st gear 500 ohm
2nd gear 800 ohms
3rd gear 1500 ohms
4th gear 2700 ohms
5th gear 6800 ohms
6th gear 15000 ohms

 

[smithabusa]

 

[smithabusa]

there is a 1K 5 volt pullup on the red wire inside the ecu

so with the bike not in a gear there is 5v on the red wire, when you start putting it in gear you get a different voltage for each gear

BLack is ground, blue is the nuetral wire, you send a ground signal to the blue wire while in neutral.

1st gear around 1.8 volts all the way up to 4.8 volts or so in 5th gear.

This is what i currently am building/selling Gear Based Controller (GBC6)

 

[AJAY]

Thanks, smithabusa. Very generous of you to offer so much info and even to dig into old stock. Your products get high marks from folks here on the forum.

I was thinking of doing this just as an engineer/geek thing to do. Maybe just make a simple 6th gear ("overdrive") indicator light using a comparator and an LED.

Thanks again. - AJ

 

[smithabusa]

that would certainly be a lot easier, I can relate on the engineer / geek thing. I am a mechanical engineer by day, never played with comparators before but next on my list of electrical stuff to play with. The GBC6 is plug and play but does it in a sort of different method that a voltage comparator.

well anyhow, if there is anything i can do to help you goof around with the project feel free to let me know.

 

[AJAY]

that would certainly be a lot easier, I can relate on the engineer / geek thing. I am a mechanical engineer by day, never played with comparators before but next on my list of electrical stuff to play with. The GBC6 is plug and play but does it in a sort of different method that a voltage comparator.

well anyhow, if there is anything i can do to help you goof around with the project feel free to let me know.

Cool. Very nice of you. All the bike junk I've been buying in my winter-induced bike fever is starting to show up - genmar, centerstand, buell footpegs, tank bra, levers, more - and I'll be busy with this stuff for awhile.

Thanks again. - AJ

 

[smithabusa]

did you buy these yet? They are a must have item LOL
Frankenstein Replacement Bolts

 

[BusaWhipped]

Here my post. Contains part numbers for the components and some other useful info.

https://www.hayabusa.org/forum/electrical-mods/25971-anyone-here-able-make-these.html

 

[AJAY]

Did some more web surfing and came up with this system on Bluegauges.com, which was pretty much what I was thinking about designing:

Gear Indicator Plans

Here's the text, and a couple of pics:

Notes:
This circuit is an example of how you can build a gear indicator for suzuki motorcycles which have an OEM gear position sensor (GPS). It basically uses comparators to compare the voltage coming from the GPS to predetermined levels and then will ground the negative lead of the appropriate LED on the display. The LED’s will be lit up in a continuous style (for example: 1st will light up the 1st LED, 2nd will light up the 1st and 2nd LED, 3rd will light up the 1st 2nd and 3rd LED’s, etc. etc.

An explanation of the parts required:

U1 = 5v regulator so that reference voltages do not vary with source voltage.

R1-R7 = The resistors form a ladder that breaks up the 5v from the voltage regulator (U1) into reference signals to determine at what voltages the LM339AN will use to ground each corresponding LED. It is important to use 1% resistors to make sure you get exact reference voltages because in the higher gears the signal is very close and there is not much gap between voltages:
The output voltages from the sensor are as follows
1st gear = 1.782v
2nd gear = 2.242v
3rd gear = 2.960v
4th gear = 3.630v
5th gear = 4.310v
6th gear = 4.660v
Neutral = 5.000v

The comparators in this circuit will turn on each LED as follows:
1st LED = Anything over 1.022v
2nd LED = Anything over 2.043v
3rd LED = Anything over 2.660v
4th LED = Anything over 3.356v
5th LED = Anything over 4.052v
6th LED = Anything over 4.526v

With this setup, Neutral will light up all 6 LEDs because it is over 4.526v. This is usually not a problem because it is difficult to get 6th gear and neutral confused. It can also be helpful because it will give you an indication if there is a false neutral situation. All lights will flicker on and off as you shift gears because for a brief instant you are in a false neutral.

R8-R13 are current limiting resistors for each display LED. This is to control the brightness of the LED and also prevents the LED’s from drawing too much current and burning out.



This circuit also has a built in dimming feature which is why there are (2) 12v sources. The first one supplies voltage to the circuit and also to the LED’s. It goes through a diode (D1) for reverse protection and then through R14. R14 keeps the LED’s dim for night riding when the high beams are usually off. It is required to be on a 12v source that is on whenever the bike is on. Since it is dark out, seeing the LED’s will not be hard. For daytime riding, when the high beams are usually on, the voltage comes from the 12v high beam circuit which also goes through a reverse protection diode (D2). There is no resistor here to allow the LED’s to shine at their maximum brightness for easy visibility in the daylight.

For clarity, some points were not connected. Letters a, b, c, d, e, or f, should be connected when the circuit is built.

 

[AJAY]

Regarding bluegauges above, I'd recommend using a single 10 element LED light bar like this one that sells for less than $1 from Digikey.

Liteon
Digi-Key Part Number 160-1067-ND
Manufacturer Part Number LTA-1000G

This would be compact compared to mounting individual LEDs and not too bright for nighttime use. Just tie together all the lights for 6 and above.

 

[AJAY]

I also found these plans for a 7 segment indicator (a digital number display)

GS500 Wiki - 7-segment LED Gear Indicator

You can download a pdf of the plans here
http://www.stanford.edu/~sanjayd/gear_indicator.pdf

With all that said, you'd probably end up spending a good bit of time, travel and $s for parts, and you still wouldn't end up with as professional a product as the BoostBySmith parts, and you wouldn't have the support or guarantee that it would work. That's kind of my conclusion for now.

 

[BusaWhipped]

:tiptoe:

 

[smithabusa]

thanks Ajay, for sure its possible to get the stuff working, i have learned over the past 6 months its definitely not just as easy as get it working on a single bike LOL. Just getting a LED setup (7 segment that is) able to be seen in the daylight can be a task, and getting filtering etc setup so that it doesn't try and toggle between gears when it loose a signal momentarily etc. Its been quite the journey, and to be honest selling them at $160 they are hardly worth the effort, the billet housings, plastic cases, small run of circuit boards, lots of assembly time etc, but they do turn out nice LOL

 

[kb7uxe]

the "wheel" or center is connected to ground.
"IF" it's in neutral, it "grounds the start reley and won't let it start.
if it's in a gear, each gear posisition has a spicific resistance value..
And is paralel fed from the ECU with a 5volt, current regulated source.
Each gear posisition grounds through a different value resistor causing
a different voltage drop on the 5volts.
ie 500ohm to ground on 5V causes a spicific drop in voltage.
that is less resistance is more current flow, since current is limited, the voltage drops.
So, 1st gear has the least resistance
and 6th gear has the most. ( actually neutral is open. )
so:
1st gear is 560 ohms, so the voltage would drop to 1.782V
and so on. . .
The ECU looks for the output voltages from the sensor are as follows
1st gear =5v @ 560 ohm= 1.782v
2nd gear = 2.242v
3rd gear = 2.960v
4th gear = 3.630v
5th gear = 4.310v
6th gear = 4.660v
Neutral = 5.000v

Pretty simple ..
I hope this helps.
Actually a simple volt meter might work. ;-)

 

[kb7uxe]

correction :
OLD
"IF" it's in neutral, it "grounds the start reley and won't let it start.
NEW
"IF" it's in neutral, it "grounds the start reley and WILL let it start.
sorry about this.
Dan.

 

[kb7uxe]

I hate to be the barer of bad news, but:
This indicator for the 550 may not work:
it shows a different wire ( individual feed ) for each gear position.
Hayabusa has only 1 wire out (with voltage differential for gear indication.)


Dan. kb7uxe..

I also found these plans for a 7 segment indicator (a digital number display)

GS500 Wiki - 7-segment LED Gear Indicator

You can download a pdf of the plans here
http://www.stanford.edu/~sanjayd/gear_indicator.pdf

With all that said, you'd probably end up spending a good bit of time, travel and $s for parts, and you still wouldn't end up with as professional a product as the BoostBySmith parts, and you wouldn't have the support or guarantee that it would work. That's kind of my conclusion for now.