Is the feed to the speedo via a CANBUS circuit?

I'm looking to temporarily fit my rally trip meter from my SJ into the Yeti for recce runs without causing any disturbance.

I can get an interface to enable this easily - hence my question.

Any rallyists out there know?

Well, Jerry, as the speedo is an electronic one that seems to use the ABS sensors as the "excitors" it must be CanBus.

Not necessarily. Electronic speedos have around for a long time before CANbus systems. And does it really use the ABS sensors for pick-up? Neat if it does, but never come across this; I would have expected the pickup to be in the gearbox.

I would take a guess at no, it's not, but don't know for sure.

I don't think the speedo is Canbus otherwise there would only only be 4 wires going to the cluster instead of the great bunches of cable that do.

Mmmm, what to do?

Is there any way I can confirm CANBUS activation of the speedo before I lash out on an adapter?

Oops! I'm obviously wrong then.

Have a look on the gear box to see if there is a speedo drive, if there is the chances are it's not on the canbus from the gearbox to the instruments.

It would make economic sense to get the speed from the ABS as the hardware is already there, then transmit the speed signal from the ABS to the engine ECU, instruments, radio and convenience ECU via the canbus.

Back to the drawing board.

I ordered the interface, but it doesn't work. A conversation with the manufacturer "sort" of inferred that the speedo drive was CANBUS, but it was not available at the OBD-11 diagnostic socket.

So I've got to rig up a sensor off the propshaft say, and route wiring in a non warranty way to the interior (possibly via the handbrake boot), or give up the idea.

The cluster is directly connected to the CAN gateway

There are a lot of wires for some of the warning lamps

Low screen wash

Brake pad sensor

Handbrake

Outside Temperature

Low Coolant

Oops! I'm obviously wrong then.

Nope, your right.

The abs system needs a vehicle speed signal so this is used by the dash cluster too.

Jerry,

A question was raised on the British Rally Forum about Tripmeters, and there was this reply which might be of interest:

""On the subject of triggers, I discovered that some ISO radio connectors on cars with electronic speedos have a wire that carries a pulse. I gather to work with radios that have automatic speed/volume control.

My MGZR had this so obviously not limited to exotic cars! One connection to that plug and trip sorted with the Romer Time. No idea if the others do this but might be worth checking.""

Don't know if it helps.

32-pin connector -T32a- :

1 - Fuel pump control unit -J538- 2 - Fuel pump control unit -J538- 3 - Fuel level sender 2 -G169- (only for vehicles with four-wheel drive) 4 - Fuel level sender 2 -G169- (only for vehicles with four-wheel drive) 5 - not assigned 6 - not assigned 7 - Immobilizer reading coil -D2- 8 - Immobilizer reading coil -D2- 9 - Speed signal - Ouput 10 - not assigned 11 - Oil level and oil temperature sender -G266- 12 - not assigned 13 - not assigned 14 - not assigned 15 - Brake lining/pad wear sender, front left -G34- 16 - Terminal 31 - Input 17 - Windscreen washer fluid level sender -G33- 18 - Coolant shortage indicator sender -G32- 19 - Ambient temperature sensor -G17- 20 - Terminal 31 - sender earth - output 21 - not assigned 22 - not assigned 23 - not assigned 24 - not assigned 25 - Handbrake warning switch -F9- 26 - Brake fluid level warning contact -F34- 27 - Oil pressure switch -F1- - Oil pressure switch for reduced oil pressure -F378- 28 - CAN H, Control unit in dash panel insert -J285- 29 - CAN L, Control unit in dash panel insert -J285- 30 - not assigned 31 - Terminal 15 - Input 32 - Terminal 30 - Input

I read that as pin D2 - 9 should be the one, but could it be "piggy-backed" to a tripmeter?

Thanks, but I've returned the interface for credit!!

My only hope is the old fashioned way, if I can find a non intrusive way into the interior from the prop shaft area.

I haven't looked at the Yeti system, but I thought that all modern cars were similar. Speed sensors on all 4 wheels (needed for the ABS) fed to the system computer to calculate actual speed (based on the standard rolling radius of the tyres); the end result available on the CanBus; the speedometer fed a slightly higher figure (or it inflates the CanBus figure) so that it can never display a speed below the actual for legal reasons.

My X-Type Jaguar speedo stopped working when an ABS reluctor ring split and fell off, which seems to confirm the source of the speed data being ABS. On my current XF I have a digital display device permanently plugged into the OBD2 port and have it set to display speed, amongst many other things - and it shows a speed which matches almost exactly with that shown on my TomTom satnag but is several mph lower than that shown on the speedometer. However, even knowing that the speed data is available on the CanBus it's a much harder task to identify how it's codified and then extract it for use elsewhere.

Just to confirm a hunch, I transferred my Scangauge out of my MG TF, and tried it in the Yeti.

It worked, speed, coolant temperature etc - no problem.

I think I'll have to ring the interface supplier again, as I've sent it back for credit