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Discussion Starter #1
Thought I'd fixed it- from my ride in the rain a few weeks ago. Put some grease on the plug, at the rear CVT case.
It worked for weeks and hundreds of miles.

Today it was cool (65) and drizzly, certainly not really raining.
And the speedo went wonky again. :(

I can't see that water got into the plug, at the instrument cluster. It wasn't raining that hard.

Any ideas?
Dealer said, they have never seen a bad sensor for these AN bikes.

Does anyone know how to test the leads, at the sensor plug (with a voltmeter), what wires = what voltage?
 

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unless you are going to stand in a swimming pool with the bike submerged, testing may not do you any good, seems to happen only when wet right? so give her a gentle bath, up on center, throttle a little above idle so mph is indicated, and take a hose and start wetting down electrical cord from back to front , slowly, (time for wonks to soak in) and find your problem, there are 2 pieces of gear that I know of that will tell you if you have a leaky wire, a megohmmeter, and a time domain reflectometer , the megger will tell you if it leaks but not where, the tdr will tell you where in inches from the end but only in certain very restricted applications, at least with the water hose she gets a good bath
 

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Is the FI lamp lit when the speedometer is not working?

I ask because the shop manual states that the ECU will throw DTC C16 if "the speed sensor signal is not input to ECM for more
than 3 sec. during the engine is running at 5 000 r/min or more.
" If the FI lamp is not lit then it would seem the sensor signal is being received by the ECU, placing the problem in the instrument cluster...

Here is the basic diagnostic info for the sensor:



With the ignition key ON there should be +12 V between the orange/red wire and the black/white wire (you will need to back-probe these or use insulation piercing probes).

Also with the key ON, if you observe the voltage between the pink and black/white wires you should see a varying voltage as you slowly spin the rear wheel. the manual does not specify the magnitude of this voltage. Check this at the sensor and at the speedometer and ECU.

There are no electrical specifications provided for the sensor; the only test being to remove it, reconnect it and with the key ON observe the output voltage on the pink wire (to the black/white wire). This is a more basic version of the test I outlined above, achieved by just spinning the wheel.

I would not be overly concerned with "leaky" wires as the frequency of the speed signal is relatively low. The sensor is "reading" the 40-tooth final drive gear. The tire spins 1890 revs per mile at 60 mph that would be 1890 revs/minute * 40 = 75,600 pulse/min, or 1.26 kH. I.e. sufficiently slow that the wire would have to be "leaky" as heck to significantly impact the wave form--which would be a rather "soft" looking pulse anyway.
 

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Discussion Starter #4
Wow, great information, thank you!
No, the FI light does not come on.
Rechecking the CVT case wire, and the connections at the instrument cluster today.

Thanks again!
 

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Note: It's just the speedo are there other Needles Acting up as well or just the Speedo Needle by itself, But there may be a chance that the Needle may be Loose on the PIN.

Not sure how these Sensors Work But there Pointed at the Gear!! which may have Magnet Properties,

So you can Rule this Part Out, i don't think this is the Problem.

So Electricity/Electronics would be the Case.
 

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The sensor is most likely a Hall effect or a proximity inductive unit. These work because the magnetic properties of the sensors are altered when a mass of steel or other magnetically conductive material passes near its business end. This change can be used to change the electrical characteristics of the sensor assembly and produce a useful signal related to the passage of the magnetic material.

In this instance the final drive gear is not a magnet, it is however made of a magnetic material and it's teeth passing by the sensor generate a vehicle speed related output signal...
 

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cliffyk said:
I would not be overly concerned with "leaky" wires as the frequency of the speed signal is relatively low. The sensor is "reading" the 40-tooth final drive gear. The tire spins 1890 revs per mile at 60 mph that would be 1890 revs/minute * 40 = 75,600 pulse/min, or 1.26 kH. I.e. sufficiently slow that the wire would have to be "leaky" as heck to significantly impact the wave form--which would be a rather "soft" looking pulse anyway.
I received a PM about the above comment and wanted to clarify same. I was referring to "leaky" in the electrical sense, as in a damaged or otherwise compromised cable have such high capacitance that it would attenuate a high frequency signal--NOT a cable that is shorting out from water intrusion, being pinched or whatever. An electrically leaky cable/conductor is distinctly different from an electrically shorted or open cable/conductor.

Such gross physical damage will of course interfere with the VSS signal and needs to be repaired...
 

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Discussion Starter #8
Now the speedometer is mostly DEAD. Except when it's cold. When the CVT case heats up, the speedo dies.
Therefore, I suspect the speed sensor (a whopping $95 FOR THE PART at the "friendly" Suzook dealer).

For $95, I had better recieve much more than a tiny, mostly plastic part and a feeble "thank you". :(

Will tap in a wire to the PINK wire, connect to voltmeter, and watch it as I ride. If there is no reading, and the CVT case is warm, I think the sensor is the culprit. What do y'all think?
 

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Go to Ebay, there's some up there for $27-$40 Bucks, TYPE Suzuki Parts, Speedo Sensor

But as you said Hook up the Voltage Read out, to the wires , First Unplug the Speedo Sensor before you run the wire Test!! and drive it, But if it's a temperature thing then that may be the Part!.


Even with out the Speedo Unit plugged in there should be a Constant Voltage readout, Try that first with out the Speedo Connected, and see if the Power Spikes from the wires First the wires May be

------------- Negative +++++Positive Straight thru Or just ------------- Negative

EXAMPLE: NEGATIVE- (SPEEDO 05H) POSITIVE+
_________PINKWIRE_______________WIRE


EXAMPLE: NEGATIVE- (SPEEDO 05H) NEGATIVE-
_________PINKWIRE_______________WIRE

Elliott,
 

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could'nt this be done more accurately and SAFELY on the centre stand ?
 

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Discussion Starter #11
WELL.
I connected a voltmeter to the PINK wire. Stuck the VOM on the fuel door. Rode until it failed.
When the speedo works, voltage is in the 1.8 to 1.9 range.

When the speedo fails, voltage is in the 1.6 to 1.7 range.

It is not temperature-dependent. The speedo works after first starting out. Then fails. But sometimes works when all is hot. At any rate, it is mostly dead now.

Thanks to all. Looks like the sensor is bad. I will try ebay :|

Such electronic problems are a pain in the arse. Especially when you can't bench test the part.... And there is no refund, if the new sensor doesn't cure the problem.
 

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Discussion Starter #12
Hmmm
Brother-in -law has a Hertz (frequency) meter. Connected it to the sensor. Coincidentally, the speedometer had quit just then.
Sensor was sending pulses. Estimated that they were of correct freq. relative to rear wheel speed (on centerstand). But voltage from the sensor was low.

Can the sensor send correct number of pulses, but fail anyway? When the speedo fails, the voltage of pulses is lower. Hmmm.

I sure hope it's not the speedometer! $$$$$$$$ :(

Oh Happy Thanksgiving!
 

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Two things that might help.

1. Have you checked to see if your bike is displaying any diagnostic codes? http://burgmanusa.com/bkb/Engine+Diagno ... uble+codes That link will show you how to use a hi-tech tool (a paperclip) to short across the diagnostic plug and get a reading on the dash. It also includes the table of what those codes mean.



2. There are some troubleshooting tips on the following pages in the service manual. They mention clearing away metal particles or foreign material. They also tell how to use a screwdriver (metal object) to see if the output voltage varies.

Chris

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