Thread: 91 RR Electronic Speedo - Pulses per Kilometer

Do u need this info for aftermarket cruise control ? Because I had the same problem trying to find this out, in the end just guessed and played around a bit until I got it right !!

matt.

Gday Matt,

No, im in the middle of Marrying up my Rover to a 5Ltr VT motor. The ECU requires an input from a vehicle speed sensor. On older model rangies with cable drive its just a case of buying a module that piggy backs off the speedo cable. In my case i need to split the signal to feed the ECU. Once I have the Rover numbers I can deal with the issue. I already have the numbers for the Holden motor.

Regards
RobG65

The unit gives 6 pulse per rev of the cable, you can work it out from here how many there are 1Km

Rob
I also seem to remember hearing you can get the speed sensor deleted fro the ecu

Gday Shaun,

Thanks for the info, I got another response with 6 pulses, but of the road wheel and not he turn of the cable. The result would be very different between the two.

Based on a the wheel senario my 245*75*16 tyres with a diameter of 755mm have a cirumference of 2434.7mm.

That means in one kilometer travelled I will have 2464.3 pulses to the speedo.

I dont want to turn the vehicle speed sensor off yet but as a last option yes I could.

Regards
Rob

Rob the book that comes with the factory injection test computor say 6 per rev of the unit. I have meaured this on my Disco when fault finding as well.

Shaun,
I finally found this on the RAVE CD.

The Vehicle Speed Sensor (X190) sends a signal to the speedomter in the form of voltage pulses. The pulses are filtered by a Vehical Speed Sensor Buffer inside the speedometer. The voltage alternates between battery voltage and 0 volts 6 times per wheel revolution.

The only thing ambigous to me here is which wheel they are talking about? And how does it relate to the number of turns of the road wheels.

Regards
Rob
PS I appreciate the help