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 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.
What does a speed sensor do?
The speed sensor does more than just control the speedometer, it also helps to control the cruise control system and may even affect the way that the engine runs. If the service engine soon light is on, then check the trouble code with an OBDII scanner.
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.
MM3 speedometer calibration
Does anyone know how to recalibrate the speedometer on the MM3 tuner? My speedometer is showing me 2mph slower than I am actually going. Thanks
Re: MM3 speedometer calibration
My 15 Ram has always been 3 off. I would set the cruise at 73 to run 70. And now with one size bigger tires tires it has reversed on me. That’s with a stock truck no tunner.
Re: MM3 speedometer calibration
Change the tire size by like .1 at a time till it gets right. My speedometer is right on now. I think it's under ECM then ABS, I can look this afternoon to comfirm.
