What is a speedometer on a golf?
A modern vehicle’s speedometer takes the input from the Vehicle Speed Sensor and sends that data to the ECU. The ECU is programmed with your Golf’s gear ratios and stock tire height. It combines this data to send the speed reading to the instrument cluster. The causes of a bad speedometer will typically be found in these four things:
What is the connection between the drivetrain and the speedometer?
Vehicles used to use a cable that would usually run from the tail shaft of the transmission to the speedometer. There was a physical/mechanical connection between the drivetrain and the speedometer. Instead of this direct connection, a modern vehicle uses the vehicle speed sensor and relays that information to the speedometer.
What is an ECU golf?
ECU – Your Golf’s Engine Control Unit (ECU for short) is the computer that takes all of the information that the vehicle sensors compile and uses it to control the vehicle systems, and sends important vehicular telemetry data to the driver via the instrument cluster.
What does it mean when a speedometer goes out?
Most of the time if the speedometer is out, it means that there is a bigger problem with the entire instrument cluster.
Jetta Forum Junkie
I need a MK3 speedo wiring diagram so I can makea loom to "clock" my new speedo cluster to the correct millage for my car, my new clocks are at 150k yet my car has done 65k, I just want to make up a loom I can power from a 12v bench supply and clock using a speedo sender and a drill. Ok its very low tech, but I no longer have access to oscilloscope and frequency generators, otherwise I'd analyse the output of the speedo sender with a scope and recreate it at a higher frequency with the waveform generator to clock it..
jamiehol Forum Member
i've upload a spreadsheet to my website, with most of the pin outs of the Mk3 clocks and corrado ones as well.
Jetta Forum Junkie
Cheers, grounded pin 5 as well displays now show IN02 (service) then the millage and the time.
Ro Forum Member
can you run a electronic speedo sensor backwards?? i think it pulses at a given rotation and sends the signal to the clocks and they count forward, surely if you run the sender in reverse it'll still pulse and the clocks will continue counting upwards???
Vento Mike Forum Junkie
I just assume he is running them until it goes back to zero then back up to his correct milage....i imagine it will take a while!