5 GT Turbo Testing the electronic speedo sensor & speedometer (5, 9, 11 Turbo)

[DaveL485]

Boffins: How do you test the speedo sensor?
How do you test the speedo?
Can you fake an input into the speedo to make it wobble? (Pulse, voltage?)

Basically we need info on diagnostics please. I fixed my R9 one by chopping out the middle connector, so never dived in any further.

 

[tutuur]

Just take the sensor out of the gearbox and move it along a piece of metal. If you do it fast enough the speedo will move

 

[DaveL485]

Just take the sensor out of the gearbox and move it along a piece of metal. If you do it fast enough the speedo will move

So it just has a pickup in the gearbox then, that works just like a crank or cam sensor?

 

[Brigsy]

Iirc its just a toothed ring on the diff

 

[Lewis]

This is the standard gtt sensor target ring.

 

[Paul B]

we used to use a target ring on an electric drill... (sander attachment) ... spin it up next to the sensor when removed, for testing... If the speedo moved it was gearbox related... if it didnt we all scratched our heads, had a few brews and made a start at the pick up and worked backwards....

 

[tutuur]

Basically works the same as a crank or cam sensor yes. VR sensor that is