speed sensor output

[Lord Popgun]

Here is the speed sensor output.

The signal rides on a ~10v level. Notice the trace is 10v from the scope center (scope 5v per cm)

Test setup: I disconnected the sensor connector from the harness and connected jumpers to the harness male pins. Then I used .028” safety wire inserted into the sensor female pins and clipped the jumpers to the safety wire. Now the speed sensor is connected to the bike again and I had a place to connect the o-scope leads (to the safety wires).

Scope: the probe was connected to the VSP+ wire. The probe ground was connected to the VSP- wire. Connecting the probe ground to chassis ground does not work. All you get is a sawtooth wave train that stays constant amplitude and frequency. Max has a theory on that.

Upon ignition turn on the trace goes from 0v to ~10v and stays there until I put the bike in gear (on the center stand). When it clunked into gear you can see a period pulses as it jerked the wheel I guess. Then I let the clutch out and the bike idles at 10MPH. You see the pulse train. Then ran the throttle up. Then took it out of gear and turned it off. You can see the pulse train is gone and the trace is at ~8v vice the 10 at start.

TLDR: started the bike, put it in gear and ran it up.
I forgot to publish it. Wait until 6:30pm. About 10-15 minutes and it should be good.

 

[Randy B]

Here is the speed sensor output.

The signal rides on a ~10v level. Notice the trace is 10v from the scope center (scope 5v per cm)

Test setup: I disconnected the sensor connector from the harness and connected jumpers to the harness male pins. Then I used .028” safety wire inserted into the sensor female pins and clipped the jumpers to the safety wire. Now the speed sensor is connected to the bike again and I had a place to connect the o-scope leads (to the safety wires).

Scope: the probe was connected to the VSP+ wire. The probe ground was connected to the VSP- wire. Connecting the probe ground to chassis ground does not work. All you get is a sawtooth wave train that stays constant amplitude and frequency. Max has a theory on that.

Upon ignition turn on the trace goes from 0v to ~10v and stays there until I put the bike in gear (on the center stand). When it clunked into gear you can see a period pulses as it jerked the wheel I guess. Then I let the clutch out and the bike idles at 10MPH. You see the pulse train. Then ran the throttle up. Then took it out of gear and turned it off. You can see the pulse train is gone and the trace is at ~8v vice the 10 at start.

TLDR: started the bike, put it in gear and ran it up.
I forgot to publish it. Wait until 6:30pm. About 10-15 minutes and it should be good.

You need to change the video from private, or only you can watch it.

 

[Lord Popgun]

I just checked and it says public and published. Try it again and let me know.

I posted here before I remembered I had to published it. Then had to a 15 minute wait for it. Sorry

 

[max]

Works fine downunder Lord Popgun, just wondering why you say it is a minus voltage, it shows on the top part of the scale, have you inverted the scope or is the trace centered on 2 div from center?

Thanks for explaining how the probe is connected, makes all the difference when trying to work out what the result is.

So now we know it is a digital sensor as opposed to Zirconxi's coil/magnet one for his ignition.

 

[pekingduck]

Just curious how you guys got on this topic, as I happen to be having problems with rear wheel speed sensors. And you're the guys I need to ask. I converted my 2017 EX from wire wheels to cast wheels from a 2014 DLX, and everything bolted up fine physically, but I was using a used 2014 rear speed sensor, and it is not reading at all.

What year speed sensor are you testing? And are you able to test them at all without a scope? Used to be able to test the 3-wire ones just passing a screwdriver over the end.

 

[Cormanus]

PD, Popgun's bike is a non-ABS 2013.

 

[pekingduck]

PD, Popgun's bike is a non-ABS 2013.

Thanks Cormanus.

 

[max]

PD if i understand it correctly you can measure the dc voltage across the sensor wires with the connector in place like lp did, as the wheel is slowly rotated to interact with the "tonewheel" as it's called you should be able to measure 8 volts dc which will vary with about one volt either way with every slot.
how fast your voltmeter reads is how fast (read slow) the wheel needs to be rotated from a slot to a ridge in the tone wheel.
If you had a speaker and a capacitor and connected those in series with the same wires you would hear a tone and the frequency would change with the speed of the wheel.

the bike needs to be switched on in both cases to supply dc power to the sensor and the gap between the sensor and the tonewheel is 0.4 mm. quite small and i can see the orientation of the sensor to line up with the gap beiing important as well since we're talking about a slot.

If nothing works you could take the sensor out and do your screwdriver test to see if the sensor is otherwise working.

 

[Lord Popgun]

Max, I had the leads reversed when I emailed you. I put them on probe to + for the video.

PD, The test setup is still installed. I’ll give Max’s test with a voltmeter a try and see what happens. I’ll try using a DVOM but I think using an analog meter will work better for that test. So I’ll try that too.

I’m not taking the sensor out for a screwdriver test, although I do have an of crankshaft position sensor from a chevy and it passes the screwdriver test

 

[PowerDubs_imp]

Popgun- would this work for the Dynojet power commander autotune box speed input sensor?

If so- it will allow to adjust fueling for each gear individually.

I just looked back at an old email from Dynojet and Dusty had replied-

"You will have to check if one of those lines is 0-5v and that it drops to zero."

 

[Lord Popgun]

PD,

I just went out to the garage and did the speed sensor test using a DVOM and then an analog meter.

With the bike ignition OFF, upon connecting the meter across the sensor leads it read ~.5v This with meter on DC, 12v scale.

Ignition ON and meter reads around 8-10v. Seems to depend on where the wheel is. I guess depending on if the sensor is reading a hole or a bar in the reluctor (or tone ring).

When spinning the wheel you can see he voltage vary, as Max said, around 1v. It is easier to see on an analog meter as the needle moves a lot (depending on scale selected) and has no processing delay that a DVOM has.

During the test I kicked the wheel backwards as I can get it to go faster. But I got the same results making it go forward. Just couldn’t spin it as fast.

Popgun- would this work for the Dynojet power commander autotune box speed input sensor?

If so- it will allow to adjust fueling for each gear individually.

I just looked back at an old email from Dynojet and Dusty had replied-

"You will have to check if one of those lines is 0-5v and that it drops to zero."

Dubs,

From what I’ve seen on the scope and the voltmeters I don’t seen this as 0-5v. Looks like they stay around 10v and the pulses vary around that. You can see that in the video.

As I’ve said, with a scope, with the probe on the sensor lead and the probe ungrounded or grounded to the chassis all I get is a constant sawtooth wave. Don’t know what it is. So I don’t know about the Dynojet. But I can go measure the voltage on the sensor pins to chassis ground with a meter just for giggles but it doesn’t look like this is a 5v circuit.
Well that was interesting. With the + meter lead on the VSP+ wire and the meter - on chassis ground (neg battery terminal) I got the same results as when reading across the sensor wires.

Ignition OFF and read ~ .5v and ignition ON read 9-10v and when spinning the wheel by foot reading would vary 1 volt or so. NO 0 to 5v.

I would imagine you could go to, say, Digi-Key and buy a logic level changer and do some home brew circuitry. Csory is into that stuff. Maybe PM or email him. He hasn’t checked in since Feb.

 

[max]

Dubs elaborating on LP's result i agree totally with his findings, but there may be another way to get your 0 to 5 volt signal out of the e.c.u.
If the speedo is using the e.c.u. for an input of it's speed indication it could be that the ecu has a 0 to 5 volt output.

That is when the rear wheel sensor drives the e.c.u. instead of the speedo itself like the early models apparently did, so have a think about that option.

Failing that i think there is a very simple way of converting the 10 volt sensor signal in a 0 to 5 volt one with a zener diode, two resistors and a small npn transistor, briefly you drop the 10 volts to a 0 to 1 volt signal by "loosing" 9 volts in the zener diode, feed that into a transistor and "collect" the output of that transistor to your input, careful selection of components would be required to not affect the rear wheel sensor's signal.

 

[PowerDubs_imp]

I wrote back to the Dynojet guy- and he said no harm in trying to plug that speed sensor wire you guys found into the power commander and see if it works.

I looked on their website at the manual- and there is no mention on the speed sensor for any requirements whatsoever- it is the other plug next to it for other trigger inputs that says 0-5v. Nothing for the speed sensor.

Does anyone have an operational bike with a power commander and a willingness to try?

 

[PowerDubs_imp]

Hi Popgun. I am 98% done getting my bike ready to be operational. Can you please let me know where the wire is you tested? I didn't see it mentioned in the thread.

 

[Lord Popgun]

For the speed sensor, follow the sensor lead to where it plugs into the bike harness. Its under the right side cover in a boot on the frame down tube.

 

[PowerDubs_imp]

For the speed sensor, follow the sensor lead to where it plugs into the bike harness. Its under the right side cover in a boot on the frame down tube.

Just getting around to play with this- what color wire am I looking for?

Thank you!!!

 

[Lord Popgun]

The speed sensor wires are Blue and white. The bike connector is G/R and P/W which is pink/white and green/red.

P/W is VSP+ and G/R is VSP-