GTS Club

[Brian Steers]

Hi folks.

I will be losing the ABS ECU on my black bike in the near future as part of it's on-going development and wonder if any of you techno-crats out there can tell me how the speedo is driven on the non-ABS equiped bikes. I know it is driven off the front wheel sensor (which I am keeping) but want to lose the ABS ECU so what informs the speedo what to show?

Help please.

Regards,

Brian

[Mr Wog]

After taking the ABS off of my bike..and sending the sensor across the pond
What a dummy !
I purchased a new sensor because I lost my speedo when I took the cable off.
I put the new front wheel sensor on along with the ABS box, and the speedo works now.
I will take the ABS box off and see if it is still working, may run off the main ECU.
If this helps at all, I'll let you know when the weather clears.
Paul
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people are like slinkies, good for nothing but fun when you toss them down the stairs

[Brian Steers]

Hi Paul.

I did a similar thing when I changed the back wheel and ABS pump many moons ago. It seems the front wheel sensor and the ABS ECU are needed to work the speedo, which is why I listed this query. How do I do without the ABS ECU is what I need to know, and how do the non-ABS bikes drive their speedos?

Regards,

Brian

[Mr Wog]

Brian
I'll talk to a mechanic I know that worked on these quite often in 93 and 94. He should know this I would think. Also I'll go to the shop tomorrow and ask about the non ABS speedo cable or drive. Have them bring it up on the parts list, and see if we can figure it out.
Paul
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people are like slinkies, good for nothing but fun when you toss them down the stairs

[24c]

I cannot see Yamaha fitting a speedo cable or drive from the front wheel or modding the speedo drive enclosure to take a mechanical pickup. The instrument dials are invidual parts. which would have been so for localization issues such as speedo...kph/mph.

It would seem much more likely that there is another black box or jumper wire mod that feeds the speedo with a pulse amplification conversion directly from the front wheel sensor. You could always experiment by tapping into the speedo feed and spinning the wheel and see what happens, a good spec multimeter would be good enough.

You'd probably get the info of a genuine Yamaha GTS micro fiche, wasn't the LE non-ABS?

Not having a spare instrument cluster means I can't add anything more positive at the moment, although I do have access to one, but my GTS time is needed elsewhere,especially when losing 5kg max of ABS kit is more problematic than doing it myself.

I can see why you're doing it Brian, those aluminium castings for the footpegs cum seat subframe support aren't the nicest out there.
(OT) Anybody see the Ducati stuff in last weeks MCN? That was a really neat alternative to die cast frame technology, minimal too, something our bikes aren't.
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The MicroSquirts are working on the GTS1000 and Thunderace EFI project

[24c]

Looking in the supplementary Service Manual New Features, it would appear there is a wiring difference in the plug that forms part of the instrument panel connector.

Also the B&W version is better than the colour one...in that it shows a tapping coming off the front sensor wire going to the ABS ECU, which is different from the colour version in the main part of the service manual, which shows a yellow/red wire going from the speedo to the ECU. This wire connects to a yellow/black one which is one that gets altered in non-ABS mode.

Obviously, the ABS light on the dash is crippled on the non-ABS model, but maybe the answer lies in the connector. It's possible the ABS ECU injects something into the line, but it doesn't make sense to me, as it's normal for an ABS ECU to monitor wheel rotation, to detect imminent lock.

So I'm guessing all you have to do is wire the wheel speed sensor into the speedo inputs directly and you should be up and running.

One way to check, is get OmegaChassis to remove his instrument panel off the idle donor bike, and fire an inductive signal from my toothed wheel engine rig up it's connectors, and see what happens...it's not my bike

PS He doesn't know anything about this yet so ssshhhh
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The MicroSquirts are working on the GTS1000 and Thunderace EFI project

[OmegaChassis]

[rooyenan]

To ABS or not to ABS seems to stay the question

I've just been studying the wiring diagrams of both the ABS and non-ABS version considering the speedo....

As far as I can see the following happens:

On the ABS version there is a White and a Black wire running from the front wheel sensor to the ABS ECU... From the ECU a Yellow/Red wire is run to the speedo, connected to the Yellow/Red position.

On the non-ABS version the White and Black wire from the front wheel sensor are run directly to the speedo!

Here the White is connected to the Yellow/Red position, while the Black is connected to the Yellow/Black position (a position not used in a ABS setup!!)

I will open up my dash one of these days and have a look at the different connectors... I'll keep you posted!!

__________

Sir Avalon
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[24c]

The're not really different connectors Ansco, different connections maybe, but the plugs are the same shape
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The MicroSquirts are working on the GTS1000 and Thunderace EFI project

[rooyenan]

[24c]

Yes, all you have to do is bend the internal tang on the respective male and female bullet/spade connector and swap them over as per the non ABS wiring diagram...and spin the wheel or go for a ride round the block...

Bit hard on the dyno bike, no engine at the moment, actually thinking about it I good always push it down the street like a kiddies scooter

Might be a good idea to take a picture first, just in case the wiring is different or age is getting the better of you.

PS Posted this poser on the listserv site , so let us know how you get on, wouldn't want to give Jose from Spain the run around.

PPS (OT) That parcel arrive yet?
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The MicroSquirts are working on the GTS1000 and Thunderace EFI project

[24c]

Just had a look at the ThunderAce/GTS dyno bike, and as the plastic is off, I thought I'd have a look see.

Ansco, save yourself some time and don't disconnect the white speedo plug on the left hand side (facing forwards/sitting on the bike) under the top fairing...the Y/R wire is there but the front wheel sensor B & W wires are nowhere to be seen..

This is the plug in the diagram as there are some missing pins and spaces in the connector.

It would appear the front wheel sensor goes straight to the ABS ECU first, so I would check the ABS ecu plug and see if there is continuity between any B & W wires there and the small white two pin plug near the top of the Omega chassis, that goes to the front wheel sensor.

I reckon if you feed either one of these wires to the Y/R wire it might work, but I think the black wire also has to go to ground or connect to the speedo as well.

Ran out of time, been working nights and I need to shut eye, after another post.
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The MicroSquirts are working on the GTS1000 and Thunderace EFI project

[rooyenan]

[24c]

[24c]